Utility Poles
Description of Strategies
Objectives
The initial objective of good roadway design, maintenance, and operation is to keep vehicles
on the road and in their respective lanes. Motorists will not purposely move onto the
shoulder unless an emergency occurs and they need to pull over to slow or stop their vehicle.
However, errant vehicles may encroach upon the shoulder and then upon the roadside,
sometimes ending in a run-off-road (ROR) crash. This guide specifically addresses
the incidents in which a vehicle leaves the roadway for any number of reasons and strikes
a pole on the roadside. The reader may find information concerning ROR crashes, crashes
at high-crash curves, and trees in high-crash locations in other related emphasis area
guides.
To reduce the number and severity of crashes involving utility poles, luminaire poles, traffic
signal supports, and other poles and supports (the terms “pole crash” and “utility pole
crash” are interchangeable), the objectives include
Reduce the hazard of specific utility poles in high-crash and high-risk locations,
Prevent placing utility poles in high-risk locations, and
Minimize the likelihood of crashing into a utility pole when vehicles run off the road.
This emphasis area is specifically identified in Goal 16 of the Strategic Highway Safety Plan,
Minimizing the Consequences of Leaving the Road. Utility pole crashes are a subset of ROR
crashes. The guide for Emphasis Area 15.1 addresses
the general subject of ROR crashes and
covers strategies aimed at reducing the consequences of ROR crashes by (1) keeping vehicles
from leaving the roadway and (2) reducing the severity of impacts after leaving the roadway.
Ideally, preventing the vehicle from leaving the roadway and staying in its appropriate
lane is preferred. The reader should refer to the other guide for strategies for keeping the
vehicle on the roadway. This briefing paper focuses on reducing the harm in utility pole
crashes after encroachment on the roadside has occurred—strategies such as removing or
relocating specific utility poles, placing utilities underground, and reducing
the severity of collisions by shielding motorists from utility poles.
Utility pole crashes are fixed-object crashes that involve vehicles leaving the traveled way,
encroaching on the roadside, and striking a utility pole. Utility poles are one of the more
substantial and most common objects that are intentionally placed on the roadside. They are
substantial in both their sheer number and their rigidity (each one representing a significant
fixed-object hazard). The only object type more frequently struck in fatal fixed-object crashes
is a tree.1 Because of the structural strength and small impact area of utility poles, these
crashes tend to be severe.
The adverse safety effects of utility poles extend beyond the ROR crash type. Utility poles
can also contribute to the severity of other crash types. Crashes are often categorized by
“first harmful event.” There are many crashes not classified as ROR, or fixed-object, crashes,
where one or more vehicles strike a utility pole. In these cases, striking the utility pole is a
secondary event that may be as severe as, or more severe than, the first harmful event.
Crashes involving utility poles as secondary events easily go unnoticed when accident
reports only identify the first harmful event.
This emphasis area deals with utility pole crashes, which involve vehicles that leave the traveled
way, encroach onto the shoulder and roadside, and strike a utility pole or guy wire. It is
also recommended that problem-identification analyses include crashes where a vehicle
strikes a utility pole as a secondary event. (One may argue that the only reason these vehicles
strike a pole is because of the initial event causing the driver to lose control of the vehicle.
A rebuttal to this argument is that most vehicles that strike utility poles are out of control
for some reason, because reasonable drivers do not purposefully run into fixed objects. In
any event, the presence or absence of a pole will usually have a measurable effect on the
severity of injuries.)
Agencies may face many challenges in developing a pole safety program. One will be
investigating the consequences of pole crashes, regardless of the culpability of the operators
of the vehicles that strike the poles. Failing to investigate and evaluate treatment of these conditions is not a cost-effective strategy. In fact, the “do nothing” option is often the more costly approach, even when neglecting the potential liability cost, which could be considerable.2
Exhibit V-1 lists the objectives and several related strategies for reducing the consequences
and frequency of utility pole crashes. It does not list all possible strategies to reduce the frequency
and severity of utility pole crashes. For example, many strategies that focus on keeping
vehicles on the roadway are not listed, but they would be very effective in reducing utility
pole crashes. The reader may refer to the guides that specifically address the ROR crash
issue for details on these strategies. These strategies can be applied in the planning, design,
construction, maintenance, and operation phases.
Given the objectives of AASHTO's Strategic Highway Safety Plan, this guide is focused on
lower-cost strategies that can be implemented relatively quickly. This implies strategies that
are focused upon “spots” (poles or pole lines) or small areas of the roadway. For perspective,
though, note that it has taken decades (probably more than a century in some states and
cities) to place the millions of poles along roadsides. For this reason, states and other agencies
should also consider including long-term strategies to make gradual improvement in
locations with less urgent or demonstrated needs. This will eventually lead to minimizing
the overall occurrence of pole crashes.
EXHIBIT V-1
Emphasis Area Objectives and Strategies
|
Objectives |
Strategies |
|
16.2 A Treat specific utility poles in high-crash and high-risk spot locations. |
16.2 A1 Remove poles in hazardous locations.(P)
16.2 A2 Relocate poles in hazardous locations further from the roadway or to a less vulnerable location.(P)
16.2 A3 Use breakaway poles.(T)
16.2 A4 Shield drivers from poles in hazardous locations.(P)
16.2 A5 Improve the drivers’ ability to see poles in hazardous locations.(E)
16.2 A6 Apply traffic calming measures to reduce speeds on high-risk sections.(T)
|
|
16.2 B Prevent placing utility poles in high-risk locations. |
16.2 B1 Develop, revise, and implement policies to prevent placing or replacing poles within the recovery area.(T)
|
|
16.2 C Treat several utility poles along a corridor to minimize the likelihood of crashing into a utility pole if a vehicle runs off the road. |
16.2 C1 Place utilities underground.(P)
16.2 C2 Relocate poles along the corridor farther from the roadway and/or to less vulnerable locations.(P)
16.2 C3 Decrease the number of poles along the corridor.(P)
|
Explanation of Strategy Types
The strategies in this guide were identified from a number of sources, including a literature
review, contact with state and local agencies throughout the United States, and federal
programs. Some of the strategies are widely used, while others are used at a state or even a
local level. Some strategies have been subjected to well-designed evaluations to prove their
effectiveness. However, many strategies, including some that are widely used, have not been
adequately evaluated.
The implication of the widely varying experience with these strategies, as well as the range
of knowledge about their effectiveness, is that the reader should be prepared to exercise caution
in many cases, before adopting a particular strategy for implementation. To help the
reader, the strategies have been classified into three types, each identified by letter throughout
the guide:
Proven (P): Those strategies that have been used in one or more locations and for which
properly designed evaluations have been conducted that show it to be effective. These
strategies may be employed with a good degree of confidence, but any application can lead
to results that vary significantly from those found in previous evaluations. The attributes of
the strategies that are provided will help the user make judgments on which is the most
appropriate for the particular situation.
Tried (T): Those strategies that have been implemented in a number of locations and that
may even be accepted as standards or standard approaches, but for which there have not
been found valid evaluations. These strategies, while in frequent or even general use, should
be applied with caution, carefully considering the attributes cited in the guide and relating
them to the specific conditions for which they are being considered. Implementation can
proceed with some degree of assurance that there is not likely to be a negative impact on
safety and very likely to be a positive one. It is intended that as the experiences of implementation
of these strategies continues under the AASHTO Strategic Highway Safety Plan initiative,
appropriate evaluations will be conducted so that effectiveness information can be
accumulated to provide better estimating power for the user and so that the strategy can be
upgraded to a “proven” one.
Experimental (E): Those strategies that are ideas that have been suggested and that at least
one agency has considered sufficiently promising to try on a small scale in at least one location.
These strategies should be considered only after the others have proven not to be
appropriate or feasible. Even where they are considered, their implementation should initially
occur using a very controlled and limited pilot study that includes a properly designed
evaluation component. Only after careful testing and evaluations show the strategy to be
effective should broader implementation be considered. It is intended that as the experiences
of such pilot tests are accumulated from various state and local agencies, the aggregate experience
can be used to further detail the attributes of this type of strategy so that it can be
upgraded to a “proven” one.
Targeting the Objectives
The first objective addresses locations that are exhibiting multiple crashes or that are
recognized as high-risk locations. The application of these strategies is generally limited to a
single pole or a few poles. For example, one pole on the outside of a horizontal curve can be
moved to a less exposed location on the inside of the same curve. The target of the second
objective is new utility poles placed along the roadway or poles that require relocation to
accommodate a 3R3 or other roadway project, including minor widening. In addition, the
second objective targets poles that will be replaced when utility companies periodically
reconstruct their facilities. The last objective targets utility poles along longer sections of
roadway where crashes are spread out along the corridor and not clustered in a small
number of poles.
For any strategy to work, it is important for partnering, communication, coordination, and
cooperation between the utility companies and highway agencies. It is important for all these
agencies to work as a team by sharing information on crashes and claims, conducting joint
field visits, and taking a proactive approach in addressing utility pole crashes. For example,
AmerenUE, a major utility company in Missouri, and Missouri DOT are working together to
identify and develop procedures involving improvements to locations where utility poles are
experiencing vehicle collisions (see Appendix 1). Florida DOT, through its partnership with
utility companies for many years, has developed a utility accommodation manual that regulates
the location, manner, installation, and adjustment of utility facilities along, across, or on any
transportation facility under the jurisdiction of Florida DOT (see Appendix 2). Pennsylvania
DOT is working with the utility companies in developing a master agreement that, if ratified,
will allow Pennsylvania DOT to pay for a portion of the cost of relocating a utility pole that is
determined to be in a hazardous location (see Appendix 3). It is in the best interest of the utility
companies to work with the highway agencies to develop a plan to reduce utility pole
crashes and to reduce the liability of these crashes.
Related Strategies for Creating a Truly Comprehensive Approach
The strategies listed above are considered unique to this emphasis area. However, to create a
truly comprehensive approach to the highway safety problems associated with this emphasis
area, related strategies may be included as candidates in any program planning process.
There are five candidate types:
Public Information and Education (PI&E) Programs—Many highway safety programs
can be effectively enhanced with a properly designed PI&E campaign. The primary goal
of PI&E campaigns in highway safety is to modify the behavior of an audience across an
entire jurisdiction, or a significant part of it. However, it may be desired to focus a PI&E
campaign on a location-specific problem. While this is a relatively untried approach, as
compared with areawide campaigns, use of roadside signs and other experimental methods
may be tried on a pilot basis. In general, PI&E campaigns do not directly reduce
crashes involving poles. One related instance in which PI&E campaigns may be effective
involves persuading the utility companies to understand the issue and their part in finding
a solution. There are, however, appropriate additional PI&E programs for related
strategies dealing with such problems as speed control, driving under the influence (DUI),
and seatbelt usage. Each of these programs can help reduce the incidence and/or severity
of crashes involving utility poles. As additional guides are completed for the AASHTO
plan, they may address the details regarding PI&E strategy design and implementation.
Enforcement of Traffic Laws—Well-designed and -operated law enforcement programs
can have a significant effect on highway safety. It is well established, for instance, that an
effective way to reduce crashes and their severity is to have jurisdictionwide programs
that enforce an effective law against DUI or driving without seatbelts. While the effectiveness
of speeding enforcement programs is less well documented, it may be appropriate to
apply such a program to reduce incidents of vehicles running off the road, and ultimately
into utility poles. When the law is vigorously enforced with well-trained officers, the frequency
and severity of highway crashes can be significantly reduced. This should be an
important element in any comprehensive highway safety program. Enforcement programs,
by the nature of how they must be performed, are conducted at specific locations.
The effect (e.g., lower speeds, greater use of seatbelts, and reduced impaired driving) may
occur at or near the specific location where the enforcement is applied. This effect can
often be enhanced by coordinating the effort with an appropriate PI&E program. However,
in many cases (e.g., speeding and seatbelt usage) the impact is areawide or jurisdictionwide.
The effect can be either positive (i.e., the desired reductions occur over a greater
part of the system) or negative (i.e., the problem moves to another location as road users
move to new routes where enforcement is not applied). Where it is not clear how the
enforcement effort may impact behavior, or where it is desired to try an innovative and
untried method, a pilot program is recommended. The application of enforcement programs
is not anticipated to be directly applicable to the strategies in this guide. However,
as noted above, the use of enforcement is appropriate for complementary strategies. As
additional guides are completed for the AASHTO plan, they may address the details
regarding the design and implementation of enforcement strategies.
Strategies to Improve Emergency Medical and Trauma System Services—Treatment of
injured parties at highway crashes can have a significant impact on the injury severity
and the length of time an individual spends in treatment. This is especially true when it
comes to timely and appropriate treatment of severely injured persons. Thus, a basic part
of a highway safety infrastructure is a well-structured and comprehensive emergency
care program. While the types of strategies that are included here are often thought of as
simply support services, they can be critical to the success of a comprehensive highway
safety program. Therefore, for this emphasis area, an effort should be made to determine
if improvements can be made to this aspect of the system, especially for programs that
focus on location-specific (e.g., corridors) or area-specific (e.g., rural areas) issues. As
additional guides are completed for the AASHTO plan, they may address the details
regarding the design and implementation of emergency medical systems strategies.
Strategies Directed at Improving the Safety Management System—The management of
the highway safety system is foundational to success. There should be in place a sound
organizational structure, as well as an infrastructure of laws, policies, etc., to monitor,
control, direct, and administer a comprehensive approach to highway safety. It is important
that a comprehensive program not be limited to one jurisdiction, such as a state DOT. Local
agencies often have the majority of the road system and its related safety problems to deal
with. They also know, better than others do, what the problems are. As additional guides
are completed for the AASHTO plan, they may address the details regarding the design
and implementation of strategies for improving safety management systems. When that
occurs, the appropriate links will be added from this emphasis area guide.
Strategies Detailed in Other Emphasis Area Guides—Any program targeted at the
safety problem covered in this emphasis area should give due consideration to the
inclusion of other applicable strategies covered in the following guides:
Objective 16.2 A—Treat Specific Utility Poles
in High-Crash and High-Risk Spot Locations
Strategy 16.2 A1: Remove Poles in High-Crash Locations (P)
General Description
This strategy targets specific poles located in high-crash locations. The locations would have
a history of pole crashes (responsive) or are in locations where the risk of future pole crashes
is likely (proactive). The locations may be identified through the crash database or utility
maintenance records. In these cases, the identification process is a responsive approach, but
a very good place to start, assuming that location descriptions are adequate to locate the
specific pole or poles. Conducting safety audits on roadways and identifying poles that are
in high-risk locations is a proactive approach.
When investigating locations with a history of utility pole crashes, an important question that
should be asked is, “Is this pole necessary?” If the answer is no, then remove the pole. In some
cases, the utility may have abandoned the pole and the pole no longer serves a purpose.
While these cases are obvious, the difficulty begins when the pole actually has a purpose,
whether the purpose is for utilities, street lighting, or
another reason. The next question is “Is there another
way to serve the same need while removing the poles
from the high-crash location?” If the answer is yes, then
consider removing the poles and relocating the function
of the pole as a countermeasure for treating the location.
EXHIBIT V-2
Series of Unnecessary Utility Poles
These unnecessary poles carry a single power cable for the pedestrian signal. The conduit hat provides power to the luminaire poles placed further from the road could have also provided service to the signal.
Exhibit V-2 shows poles close to the roadway that are
not necessary. The purpose of these poles is to carry the
power to one pedestrian-actuated signal. The power is
provided from another signal approximately 1.4 mile from
the pedestrian crossing. This location had a history of
vehicles running off the road and striking poles, and the
city relocated all the streetlights farther from the road.
However, that project did not affect the poles serving the
pedestrian signal because the state DOT owned these
poles. These poles continued to be struck by vehicles but
were unnecessary because the power for the pedestrian
signal could have been provided via the same conduit
used for the streetlights. As much as this is an example
of an unnecessary pole too close to the roadway, it is
also an example of why DOTs need to improve the
communication between themselves and local agencies.
See Appendix 4 for an example of one state’s approach
to relocating utilities to improve roadside safety.
EXHIBIT V-3
Strategy Attributes for Removing Select Poles (P)
| Attribute |
Description |
| Technical Attributes |
|
Target |
Poles hit by drivers of errant vehicles at specific “spot” locations where there have
been a history of pole crashes, or poles located in potentially high-risk locations,
such as the outside of a curve, end of lane drops, and in traffic islands.
|
|
Expected Effectiveness |
While this strategy does not prevent the vehicle leaving the roadway, it does provide
a mechanism to reduce the severity of a resulting crash. If the pole is not there, then
it cannot be struck. The effectiveness of the strategy in reducing the severity of the
crash depends largely upon remaining conditions after the pole is removed. For
example, if there are trees or other fixed objects remaining, then the impact may
simply be transferred to another object type. If the shoulder is steep and contributes
to vehicles overturning, then the problem is shifted to a different sequence of events
without really improving the overall safety at the location.
|
|
Keys to Success |
The keys to success include being able to identify locations and removing the
appropriate poles.
An accurate and detailed safety information and maintenance record system is
essential for this strategy to be feasible (see the description on page V-6 of “Strategies
Directed at Improving the Safety Management System”). In the absence of
such systems, one must rely on local knowledge and a monitoring process.
The use of standardized investigation forms and documentation for site
investigations is important to provide the data for decision making. This helps
ensure that site investigations are consistent across different regions and promotes
rapid site evaluation.
|
|
Potential Difficulties |
Utility pole crashes can induce a considerable amount of litigation. Well-documented
investigations serve two purposes: (1) to help determine the best remedial action to
take and (2) to provide documentation for actions taken or not taken.
On tangent sections of roadways where there are high frequencies of pole crashes,
removing a pole may lead to the crashes migrating to the next available pole. In
these cases, it is very important to understand why the vehicles are leaving the
roadway in the first place. Refer to the ROR guide for specific strategies.
|
|
Appropriate Measures and Data |
Process measures include the number of sites investigated, the number of poles
removed from the roadside, and the cost to remove the poles.
Impact measures include the number, severity, and rates of target crashes. In this
case, the target crashes should include all ROR, fixed-object crashes and any
crashes involving poles at the specific site. Evaluations should consider the overall
severity of the targeted crashes to determine that there was an actual safety
improvement and not a problem transferal. To account for crashes migrating to the
next available pole or other object, it is prudent to make the study area large enough
to cover the problem area. If the study area is too small, then the crashes may have
migrated beyond the boundaries and go undetected in the evaluation.
|
|
Associated Needs |
None identified.
|
| Organizational and Institutional Attributes |
|
Organizational, Institutional, and Policy Issues |
Pole removal programs require regular participation of the utility companies, which
own most of the poles. The utility companies should be involved at an early stage in
the programs.
New or revised policies may be needed to ensure consistent and appropriate pole
removal, as well as to facilitate cooperation with utility companies.
|
|
Issues Affecting Implementation Time |
Review time for utility companies may extend the implementation period to beyond a
year.
|
|
Costs Involved |
The cost of removing a single pole includes relocating all services carried on the
pole, as well as removing the actual pole. Determining the financial responsibility of
removing the pole is necessary. In some jurisdictions, if the pole is located on public
right-of-way and becomes a hazard to the traveling public, then it is the responsibility
of the pole owner to remove or relocate it.
|
|
Training and Other Personnel Needs |
None identified.
|
|
Legislative Needs |
There may be situations where utility companies have rights regarding poles in
public rights-of-way that allow the utility companies to ignore or reject requests for
removal. Law changes may be appropriate where a more balanced and responsive
relationship is desired.
|
| Other Key Attributes |
|
None identified. |
Strategy 16.2 A2: Relocate Poles in High-Crash Locations Farther from the
Roadway and/or to less Vulnerable Locations (P)
General Description
This strategy targets specific poles located in high-crash locations, i.e., locations that have a
history of pole crashes or that are placed where the risk of future pole crashes is likely. Highcrash
locations are to include only poles considered necessary, i.e., poles for which no
alternatives exist to provide the service carried by the poles.
FHWA's Program Guide: Utility Relocation and Accommodation on Federal-Aid Highway Projects,
Sixth Edition—January 2003 (http://www.fhwa.dot.gov/reports/utilguid/if03014.pdf)
states the following as one of the criteria for federal participation in utility relocation: “The
utility relocation involves implementing safety corrective measures to reduce the roadside
hazards of utility facilities to highway users.”
O'Day (1979) found in Michigan that vehicles are more likely to run off the road on the
outside of curves than on the inside (see Exhibit V-4). This is also intuitive to any driver who
has rounded a curve and experienced the centrifugal force. Therefore, it is reasonable that
poles placed along the outside of curves are more likely to be struck by errant vehicles.
Exhibit V-5 is a photograph of a high-speed rural road where utility poles have been placed
less than 15 feet from the outside of a horizontal curve: these locations were found to be
associated with frequent utility pole crashes due to vehicles running off the road. In the case
of isolated curves immediately downstream from long tangent sections, relocating poles
may be particularly important because these locations are susceptible to ROR crashes. There
are two alternatives to support the poles: (1) with a small number of breakaway strain poles
on the outside of the curve and (2) with compression struts on the inside of the curve.
EXHIBIT V-4
Curve Direction and Crash Frequency
Source: O'Day, 1979
EXHIBIT V-5
High-Speed Rural Road with Utility Poles Less than 15 Feet from the Edge of the Outside of a Horizontal Curve
This site has experienced several utility pole crashes due to vehicles running off the road.
Lane drops, intersections, and sections where the pavement narrows are locations where
drivers may inadvertently leave the roadway. Exhibit V-6 shows an example of a pole in a
vulnerable location after a lane drop. A similar situation may occur after widening the road
surface for turn lanes or when the pavement narrows for other reasons. Exhibit V-7 shows a
T-intersection that has experienced frequent collisions with utility poles because vehicles run
off the road as they make a left turn.
In most cases, poles are not placed in the roadway. However, placing poles on traffic islands puts poles very close to
the traveled way. Traffic islands serve purposes for channelization, directional separation, and placing small signs. Not
only can poles interfere with drivers' line of sight, but also they are often in areas that may be traversed by errant
vehicles. There are similar issues with placing poles in the medians of divided highways (see Exhibit V-8).
EXHIBIT V-6
Schematic Diagram of a Pole in a Vulnerable Location at the End of a Lane Drop
Source: Ivey and Mak, 1989, Photo: Lacy
EXHIBIT V-7
T-Intersection that Has Experienced Frequent Utility Pole Crashes when Left-Turning Vehicles Lose Control and Run Off the Road
See Appendix 4 for an example of one state's approach to relocating utilities to improve
roadside safety.
EXHIBIT V-8
Schematic Diagram of Poles Placed in Vulnerable Locations on Traffic Islands and in a Median
Source: Ivey and Mak, 1989
EXHIBIT V-9
Strategy Attributes for Relocating Poles in High-Crash Locations (P)
| Attribute |
Description |
| Technical Attributes |
|
Target |
Poles struck by errant vehicles at specific “spot” locations where there have been a history
of pole crashes, or poles in locations such as the outside of a curve, end of lane drops, and
in traffic islands.
|
|
Expected Effectiveness |
Zegeer and Parker (1984) and Zegeer and Cynecki (1984) found that crashes decreased as the
distance between the poles and the roadway increased. Large improvements were observed
by moving the poles at least 10 feet from the roadway. As the offset4 was increased beyond
10 feet, the safety effects increased but at a slower rate. Exhibit V-9A shows the expected percent
reduction in crashes (crash reduction factors) as poles are moved away from the roadway
for ADT = 10,000 and pole density = 40 poles/mile. The crash reduction factors were not found
to change significantly for different ADT and pole density values (crash reduction factors for
different combinations of ADT and pole density are available from Zegeer and Cynecki, 1984).
The crash reduction factors shown in Exhibit V-9A assume no other roadside fixed objects
apart from the utility poles. To account for the presence of other roadside objects, Zegeer and
Cynecki (1984) developed roadside adjustment factors that are discussed in Appendix 5.
EXHIBIT V-9a
Schematic Diagram of Poles Placed in Vulnerable Locations on Traffic Islands and in a Median
Source: Ivey and Mak, 1989
|
|
Keys to Success |
An accurate and detailed safety information and maintenance record system is essential for
this strategy to be feasible. In the absence of such systems, one must rely on local
knowledge and a monitoring process.
The use of standardized investigation forms and documentation for site investigations is
important to provide the data for decision making. This helps ensure that site investigations
are consistent across different regions and promotes rapid site evaluation.
|
|
Potential Difficulties |
If there are other nearby fixed objects in addition to the poles, relocating the poles may not
have the desired effect if the other objects are not treated. In these cases, if the remaining
objects continue to be involved in crashes, the expense of relocating the pole may not be
justified. Transferring the object struck to another object type or crash type that is as severe
is not an acceptable outcome.
|
|
Appropriate Measures and Data |
Process measures would include the number of sites investigated, the number of poles
relocated, and the cost to relocate the poles.
Impact measures include the number, severity, and rate of target crashes. In this case, the
target crashes should include all ROR, fixed-object crashes and any crashes striking poles
at the specific site. The impact should consider the overall severity of the target crashes to
determine that there was an actual safety improvement and not a problem transferal. To
account for crashes migrating to the next available pole or other object, it is prudent to make
the study area large enough to cover the problem area. If the study area is too small, then
the crashes may have migrated beyond the boundaries and go undetected in the evaluation.
|
|
Associated Needs |
None identified.
|
| Organizational and Institutional Attributes |
|
Organizational, Institutional, and Policy Issues |
Pole relocation programs require a regular participation of the utility companies, which own
most of the poles. The utility companies should be involved at an early stage in this
program.
New or revised policies may be needed to ensure consistent and appropriate pole
removal, as well as to facilitate cooperation with utility companies.
|
|
Issues Affecting Implementation Time |
Review time for utility companies may extend the implementation period to beyond a
year.
|
|
Costs Involved |
The cost of relocation of a single pole involves placing the pole in a new location, moving
the utilities, and providing proper support for the poles.
|
|
Training and Other Personnel Needs |
None identified.
|
|
Legislative Needs |
None identified.
|
| Other Key Attributes |
|
None identified. |
Strategy 16.2 A3: Use Breakaway Devices (T)5
General Description
This strategy targets specific poles located in high-crash locations where removing or relocating
the poles is not feasible or cost-effective. The locations have a history of pole crashes
or are in locations where the risk of future pole crashes is likely. The application of breakaway
devices is directed at reducing the severity of the pole crashes. The unforgiving nature
of a traditional utility pole contributes to the severity of the crash by causing vehicles to
rapidly decelerate. Studies of non-breakaway poles show that about 31 percent of the poles
are knocked down or severely damaged upon impact (Mak and Mason, 1980). This means
that the vehicles striking the poles absorb a sizable amount of the energy (via the crush) created
by the crash. Breakaway poles allow vehicles to pass through the pole and therefore do
not require the vehicle to absorb as much energy. Breakaway poles are designed so that service
will not be interrupted in the case of a crash.
While there are several designs and techniques for breakaway devices, only the steel
reinforced safety pole was specifically designed for utility poles. The original design was
funded by the FHWA and has gone through modifications. The latest design is called the
AD IV (Ivey and Scott, 2004; Alberson and Ivey, 1994). For a depiction of the device, see
Appendix 11. The criteria for applying breakaway devices are as follows:
The pole is located in the clear zone area.6
The alternatives for removing and relocating the poles are not practical because of right-of-way constraints, roadside environment, or economics.
The pole is a class 4–40 or smaller and does not have heavy devices attached.
There is a safe recovery area behind the pole, free of roadside hazards.
The pole is not located near a zone of significant pedestrian activity.
The final position of the pole and conductors (wires) should not create a hazard for pedestrians, other vehicles, and adjacent property owners.
In addition to utility poles, guy wires can reduce the recovery area and make the pole a larger
target. The use of breakaway guy wires should be considered where guy wires are deemed
necessary. Foster-Miller, Inc., under a Small Business Innovation Research (SBIR) study,
designed, tested, and developed a protruded fiberglass link for a breakaway guy wire.7
UTD, Inc., also designed, tested, and developed four different versions of a steel link for a
breakaway guy wire,8 also under an SBIR study. In the mid 1980s, the Texas Transportation
Institute designed, crash tested, and developed a non-proprietary breakaway guy
wire that consists of a 6-foot-long section of 3/4-inch galvanized steel pipe (Ivey and
Morgan, 1986).
EXHIBIT V-10
Strategy Attributes for Using Breakaway Devices (T)9
| Attribute |
Description |
| Technical Attributes |
|
Target |
Poles being struck by vehicles in locations where removing and relocating the poles
are not feasible or cost-effective.
|
|
Expected Effectiveness |
Field data from Massachusetts (five crashes) indicate that in the limited applications,
there have been no serious injuries from crashes involving the AD-IV steel reinforced
safety pole. In addition, there has been no loss of service, there have been no safety
problems relative to lineworkers, and the average repair time is 90 minutes.
Texas reported one crash involving the AD-IV design pole. This crash did not involve
a serious injury, although erosion had reduced the pole's effectiveness. The pole
was replaced and the side slope restored to a functional condition.
|
|
Keys to Success |
Identify specific locations where a breakaway device is an acceptable option. These
locations do not have other nearby fixed objects on the roadside and the potential
for removing or relocating the poles is poor.
An accurate and detailed safety information and maintenance record system is
essential for this strategy to be feasible. In the absence of such systems, one must
rely on local knowledge and an effective monitoring process.
The use of standardized investigation forms and documentation for site investigations
is important to provide the data for decision making. This helps ensure that site
investigations are consistent across different regions and promotes rapid site
evaluation.
|
|
Potential Difficulties |
Breakaway devices will require modest periodic maintenance and repairs
subsequent to collisions that would not be necessary if the poles were removed or
relocated to less vulnerable locations.
|
|
Appropriate Measures and Data |
Process measures of program effectiveness would include the number of breakaway
devices placed in service, the frequency of inspections and maintenance, the initial
cost, and the cost to repair and maintain the devices.
Impact measures include the number, severity, and rates of target crashes. In this
case, the target crashes are those crashes that strike the specific poles before and
after the installation of the breakaway devices. Monitoring these crashes can help
determine proper installation or other issues specific to the devices.
|
|
Associated Needs |
None identified.
|
| Organizational and Institutional Attributes |
|
Organizational, Institutional, and Policy Issues |
Pole replacement programs require a regular participation of the utility companies,
which own most of the poles. The utility companies should be involved at an early
stage in this program.
New or revised policies will be needed to establish design criteria and warrants for
placement of the new types of poles, as well as to facilitate both consistent and
appropriate pole replacement and cooperation of utility companies.
|
|
Issues Affecting Implementation Time |
Review time for utility companies may extend the implementation period during the
first installations.
|
|
Costs Involved |
Both initial and maintenance costs must be considered. Some specific cost figures
may be found in Appendix 6.
|
|
Training and Other Personnel Needs |
The affected utility companies will need to be trained in how to properly install,
repair, and maintain the devices used on their poles.
|
|
Legislative Needs |
None identified.
|
| Other Key Attributes |
|
If the breakaway devices used are not the type that can be repaired, then
replacement devices need to be inventoried. |
Information on Agencies or Organizations Currently Implementing this Strategy
The following states have applied the Steel Reinforced Safety Poles (Ivey and Scott, 2004):
In 1987, Kentucky installed 10 poles using the FHWA design. Because of roadway
projects, only 6 poles remain in service. These poles have not been involved in collisions.
In 1990, Massachusetts installed 19 poles. One pole has been struck three times and
performed as designed. However, the pole was replaced by a conventional pole because
of the failure in the wood adjacent to the through bolts in the upper connection. Eighteen
poles are still in service.
In 1991, Virginia installed five poles. These poles have experienced no maintenance
problems, have survived several instances of high winds, and have not been involved in
a collision.
In 1994, Texas installed six poles. One collision has been recorded without significant
injury to the driver.
Strategy 16.2 A4: Shield Drivers from Poles in High-Crash Locations (P)
General Description
The target of this strategy is poles in high-crash locations where removing, relocating, or
redesigning the poles (i.e., redesigning the poles as breakaway) is not feasible or not cost-
effective. This strategy shields the driver from striking the poles by using a number of
different devices such as guardrail, crash cushions, and concrete barriers. However, the
potential hazards of the safety device itself must be considered in the economic analyses.
These devices may themselves be struck by vehicles and are designed to markedly reduce
the severity of a crash, not to prevent the crash.
Guardrails and Other Roadside Barriers
The purpose of guardrails and other roadside barriers (e.g., Jersey barriers) is to redirect errant
vehicles away from a roadside hazard so drivers may regain control of the vehicle or arrive at
a safer stop than would result from striking the hazard. Shielding drivers from poles is a
proper use of guardrails when based upon engineering judgement or a cost-effectiveness study.
A cost-effectiveness study should consider the type of barrier and end treatment proposed, as
well as the level of injuries that are expected to occur from a vehicle striking them. The
methodology for conducting a cost-benefit analysis can be found in the AASHTO Roadside
Design Guide. The criteria for the application of guardrails to shield utility poles are as follows:
The pole is located in the clear zone area.
The alternatives for removing and relocating the poles are not practical because of rightof-
way constraints, roadside environment, or economics.
Breakaway poles cannot be used because of utility load, size of pole, or other requirements.
The guardrail and the end treatments or barrier will not create a greater hazard than
the poles.
The guardrail will not redirect the vehicles into a higher-crash roadside area.
The face of the guardrail will not be closer than 2 feet from the edge of the travel lane.
The guardrail should be placed far enough in front of the object that a vehicle does not
impact the object by knocking the guardrail backward.
Crash Cushions
The purpose of crash cushions is to shield vehicle occupants from rigid objects that cannot be
removed, relocated, or made breakaway. Engineering judgement or an economic analysis may
justify the use of crash cushions to treat poles in high-crash locations. Crash cushions reduce
the severity of crashes from that which would take place if the vehicle hit the unshielded
object. They do this by absorbing the energy of errant vehicles in a controlled manner. The
criteria for the application of crash cushions to shield utility poles are as follows:
The pole is located in the clear zone area.
The alternatives for removing and relocating the poles are not practical because of rightof-
way constraints, roadside environment, or economics.
There is adequate space between the travel lane and in front of the pole to accommodate
the selected crash cushion.
The final resting position of the crash cushion, the debris from the crash cushion, and the
impacting vehicle will not cause a hazard to other vehicles.
There should be a sufficient clear zone area around the crash cushion to provide for
redirected vehicles.
EXHIBIT V-11
Strategy Attributes for Shielding Poles in High-Crash Locations (P)
| Attribute |
Description |
| Technical Attributes |
|
Target |
Poles that cannot be removed from the roadside or relocated to less vulnerable
locations or cannot be treated with a breakaway device. Occupants of vehicles that
crash with these poles.
|
|
Expected Effectiveness |
These devices are traditionally used along roadsides to protect vehicle occupants from
a variety of fixed objects. However, the effectiveness of the devices depends largely
upon how close they are to the roadway and the specific design of the devices. With so
many factors influencing the crash severity and the change in crash frequency, it is
difficult to provide a simple table for expected effectiveness. Agencies are referred to
the FHWA computer program ROADSIDE 5.0 of the Roadside Design Guide to complete
economic analyses of the existing and proposed conditions. The economic analysis
is necessary to determine if the benefits of shielding the poles outweigh the
disadvantages.
|
|
Keys to Success |
A key to success is developing an effective process to identify poles in high-crash
locations and to establish an effective set of criteria concerning where to shield poles
instead of removing or relocating the poles.
An accurate and detailed safety information and maintenance record system is
essential for this strategy to be feasible. In the absence of such systems, local
knowledge must be tapped and an effective monitoring system established.
The use of standardized investigation forms and documentation for site investigations is
important to provide the data for decision making. This helps ensure that site
investigations are consistent across different regions and promotes rapid site
evaluation.
Another key to success is proper maintenance of the shielding devices.
|
|
Potential Difficulties |
The devices that are used to shield roadside hazards are fixed objects that may
themselves be struck by errant vehicles. A major pitfall can be expending resources in
the name of safety, but experiencing no net improvement or even a net degradation
in safety.
|
|
Appropriate Measures and Data |
Process measures for a program would include the number and type of safety devices
placed into service, the number and length of the locations treated, and the cost.
Impact measures include the number, severity, and rate of target crashes. In this case,
the target crashes are those that strike the specific poles or the specific safety device
after it is installed. It is also necessary to consider the number and severity of all
crashes that strike the safety device used at the specific site to ensure that there is a
net safety improvement. Monitoring these crashes can help determine proper
installation and maintenance of the roadside hardware used.
|
|
Associated Needs |
None identified.
|
| Organizational and Institutional Attributes |
|
Organizational, Institutional, and Policy Issues |
New or revised policies may be needed to ensure consistent and appropriate pole
shielding.
|
|
Issues Affecting Implementation Time |
To be determined.
|
|
Costs Involved |
The types of roadside devices for shielding drivers from roadside hazards are relatively
common, and the best sources for construction and maintenance costs are the
individual DOTs.
|
|
Training and Other Personnel Needs |
None identified.
|
|
Legislative Needs |
None identified.
|
| Other Key Attributes |
|
None identified. |
Strategy 16.2 A5: Improve the Drivers' Ability to See Poles
in High-Crash Locations (E)
General Description
This strategy is generally used when the first four strategies are not feasible or cost-effective.
In this strategy, the pole is delineated or lighted to make the pole more visible. For example,
Pennsylvania DOT has started introducing reflective taping on utility poles to improve the
driver's ability to see these poles at night (see Exhibit V-12). While this strategy does not
reduce the severity of the crash, it may help drivers see the object and take the necessary
evasive actions. This line of reasoning assumes that the errant vehicles are under some level
of control or can be brought under control after the driver is alerted to the presence of the
pole. However, if the vehicle is out of control, then the fact that the pole is delineated or
more visible does not reduce the probability of the crash.
A major problem with this strategy is that its low cost may make it appear attractive,
but it may not provide any real improvement in safety. Application of this strategy
should be limited to poles where other strategies cannot be applied. The AASHTO
Roadside Design Guide places the order of preference for treating objects in the clear zone
as follows:
Redesign the facility to reduce ROR crash potential (new or redesigned roads).
Remove the object; relocate the object.
Redesign the object to lessen the impact; shield the object.
Delineate the object.
Effective maintenance is also important. Exhibit V-13 shows an object marker behind a
utility pole. The marker had previously been in front of a pole. That pole was struck and
replaced, but the marker was never moved. This marker has since been removed because it
proved ineffectual in preventing the crash.
EXHIBIT V-12
Reflective Taping Used by Pennsylvania DOT
EXHIBIT V-13
New Pole Placed in Front of Object Marker
An object marker failed to prevent the crash that took out the original pole it
delineated. The new pole was placed in front of the object marker.
(Photo: Brian Murphy)
EXHIBIT V-14
Strategy Attributes for Improving the Drivers' Ability to See Poles in High-Crash Locations (E)
| Attribute |
Description |
| Technical Attributes |
|
Target |
Involves poles where other strategies cannot be applied or are not cost-effective.
Targets the driver of the errant vehicle, by informing the driver of the presence of the
pole, when it might not otherwise be detected before the crash.
|
|
Expected Effectiveness |
The low cost of signing and other delineating devices may show large returns in terms
of cost-benefits, if a reduction in crashes is assumed. However, it is difficult to predict
this strategy's effectiveness, because most errant vehicles are out of control and cannot
be maneuvered around objects. The strategy is experimental and may produce no
benefits. Pilot testing, with carefully designed evaluation, is appropriate here.
|
|
Keys to Success |
A key to success is establishing effective criteria to indicate when delineating the poles is
the cost-effective treatment, such as on very low-volume roads and where application of
other strategies is not cost-effective. It is important, in such cases, that the investigation
and the justification for not recommending a more effective strategy be fully documented.
Another key to success is effective maintenance. Delineation devices must be regularly
cleaned and replaced. When poles are replaced, delineation devices must be replaced
properly (see Exhibit V-13).
|
|
Potential Difficulties |
Delineating the object may not have the desired effect in reducing pole crashes at the
location. If pole crashes continue to occur at the location and the delineators are
replaced after each crash, then simply delineating the pole is not effective and other
countermeasures need to be considered.
If a delineated pole is struck, the driver may sue the highway agency, arguing that by
delineating the pole, the agency recognized the pole as a hazard and had the duty to
provide a superior treatment.
|
|
Appropriate Measures and Data |
Process measures of program effectiveness would include the number and type of delineation
devices placed into service and the number and length of the locations treated.
Impact measures include the number, severity, and rate of target crashes. In this case,
the target crashes are those crashes that involve striking the specific poles, all ROR
fixed-object crashes, and any crash where a pole was struck at the specific site.
|
|
Associated Needs |
None identified.
|
| Organizational and Institutional Attributes |
|
Organizational, Institutional, and Policy Issues |
New or revised policies may be needed to ensure consistent and appropriate pole
delineation or lighting.
|
|
Issues Affecting Implementation Time |
To be determined.
|
|
Costs Involved |
The cost of signing and other delineating material is low. However, the material may
require maintenance, as well as occasional testing for retroreflectivity.
|
|
Training and Other Personnel Needs |
None identified.
|
|
Legislative Needs |
None identified.
|
| Other Key Attributes |
|
None identified. |
Strategy 16.2 A6: Apply Traffic Calming Measures to Reduce Speeds
on High-Crash Highway Sections (T)
General Description
The application of this strategy is generally for urban residential and collector streets, where
the poles are placed close to the roadway and it is not economically feasible to remove, relocate,
or shield the poles. These roads are not typically high-speed roads, but they may have
poor speed compliance that contributes to vehicles striking poles on the roadside. Implementing
traffic calming measures to achieve lower speeds at high-crash locations can reduce
the severity of the crash by decreasing the energy of the crash. Lower speed may also have
some influence on reducing the frequency of crashes as well. This strategy should not be
interpreted as simply reducing the speed limit, especially if the speed compliance is already
low. Traffic calming measures may also divert traffic from these roads, thus reducing the
exposure. This guide is not intended to serve as a reference for traffic calming measures.
More details are provided in the pedestrians’ guide. An excellent source for additional information
about traffic calming measures is the Institute of Transportation Engineers web site
(www.ite.org/traffic/index.html).
Objective 16.2 B—Prevent Placing Utility Poles
in High-Crash Locations
Strategy 16.2 B1: Develop, Revise, and Implement Policies
to Prevent Placing or Replacing Poles within the Recovery Area (T)
General Description
This strategy involves developing and implementing policies that prevent placing (or replacing)
poles within the recovery area along streets and highways during new construction,
widening, and other projects that will affect existing or new poles. This is primarily a proactive
systemic strategy. It is designed to prevent pole crashes by requiring that each pole in a
project's boundaries be reviewed to determine the level of risk to drivers and treated if necessary.
An example of a state policy on utility placement may be found in Appendix 4
(WSDOT, 1992 and 2002). Examples of state studies that lead to policy formulation may be
found in Appendix 7, Appendix 8, and Appendix 9. Information about roadside safety policies
formulated by utility companies may be found in Appendix 10.
There are frequent opportunities to apply the products of this strategy throughout the
normal operations of a transportation agency. The design and construction of new facilities
are obvious opportunities. However, roadway widening and other low-cost projects occur
more frequently than new construction, so policies in these areas would be used more
frequently.
New roads typically offer the greatest opportunity to meet highway safety objectives.
Agencies should require poles to be placed near the edge of the right-of-way, or as far from
the traveled way as possible. 3R and widening projects are also good opportunities to
relocate the poles further from the roadway or to better locations. Typically, many smaller
widening projects result from residential development where the developer pays to widen
the road to add turn lanes. Utility placement and relocation policies should also cover these
smaller more localized projects. These projects should require improvements to the roadside
if widening degrades the roadside safety. Moreover, the policies should cover the placement
of poles for signal supports.
EXHIBIT V-15
Strategy Attributes for Developing, Revising, and Implementing Policies to Prevent Placing or Replacing Poles
within the Recovery Area (T)
| Attribute |
Description |
| Technical Attributes |
|
Target |
Poles located within the boundaries of roadway construction, reconstruction, widening,
etc., that can be relocated farther from the roadway or revised in some way to reduce
the probability of errant drivers striking them in the future.
|
|
Expected Effectiveness |
Changes often take considerable time to develop sufficient data to analyze. The
effectiveness of the strategy is dependent upon three main factors: (1) the policies
themselves, (2) the level of implementation, and (3) the frequency of exceptions.
|
|
Keys to Success |
If the policies are too weak, then they will be ineffective. If the policies are too strict,
then gaining support will be difficult. The policies must address several issues such as
the lateral displacement of encroaching vehicles, the purpose of the roadway, the
location of underground utilities, roadside conditions, the prevailing speed of the
roadway, and the volume of the roadway.
It is practically impossible to develop policies that fit every situation; therefore, there will
be exceptions. However, all exceptions should require a cost-effectiveness study and
an engineering recommendation. A large number of exceptions reduces the
effectiveness of the strategy and encourages other exceptions.
Inclusiveness is also important to attain success. When developing utility pole placement
policies, the agency should include representatives from the traffic safety, design,
legal, and utilities divisions of agencies. Developing and adopting policies with the participation
of all stakeholders is important. It is also important to gain “buy-in” from the
upper management of the highway agency.
|
|
Potential Difficulties |
Many states and local DOTs may already have policies in place that specifically address
the use of the roadway right-of-way by utilities. There may be resistance to change.
However, it is prudent to review the policies and determine if they contribute to development
of safer roadsides. In addition, the application of the policies may not be consistent
throughout the agencies.
In many jurisdictions, the agencies responsible for the design and approval of the
placement of poles along the roadside may not be familiar with the safety implications
of the roadside environment.
|
|
Appropriate Measures and Data |
Process measures of program effectiveness would include the adoption of the desired
policies, the number of projects covered by the policies, the total mileage covered, and
the number of exceptions granted to the policy.
Impact measures include the number, severity, and rate of target crashes on locations
meeting the policy requirements. In this case, the target crashes are those crashes
within the project boundaries that strike poles, all ROR, fixed-object crashes, and any
crash where a pole was struck at the specific site.
|
|
Associated Needs |
A brochure may be needed to inform field engineers, utility company personnel, and
individuals of the requirements for placing or replacing poles along the roadway
right-of-way.
|
| Organizational and Institutional Attributes |
|
Organizational, Institutional, and Policy Issues |
State DOTs and many local agencies have the organizational structures to implement
this strategy. On new construction and changes to the existing roadway, engineers
responsible for the inspection and acceptance of the work would also ensure that the
policies are applied. A key to success is establishing organizational mechanisms for
including all stakeholders in the development of the policies.
|
|
Issues Affecting Implementation Time |
Involving a range of stakeholders may affect the implementation time. Dissemination of
the policy may also take time, depending upon the organizational structure of the agency.
|
|
Costs Involved |
The key cost component is the personnel time required to develop, review, and revise
the placement guidelines.
|
|
Training and Other Personnel Needs |
Training currently provided to design engineers, construction engineers, and those persons
responsible for reviewing and approving plans needs to cover the policies concerning
the placement of poles along the roadside. Emphasis needs to be placed upon the
connection between highway safety and the policies that have been established.
|
|
Legislative Needs |
None identified.
|
| Other Key Attributes |
|
Where safety audits are performed, this policy should be reflected in the review of
existing sites. |
Objective 16.2 C—Treat Several Utility Poles along
a Corridor to Minimize the Likelihood of Crashing
into a Utility Pole if a Vehicle Runs Off the Road
This objective, unlike Strategy 16.2 A1, has a corridor orientation. The first objective focused
upon specific high-crash locations where vehicles were striking poles (e.g., on the outside of
a curve). Strategy 16.2 A2 is a systemic, proactive strategy that helps prevent placing poles
in vulnerable locations. However, some pole problems are not confined to a short distance
and are located on roadways where there are no plans for reconstruction. Thus new policies
would not affect the placement of poles on those roadsides.
Corridors where poles are placed within the recovery area (i.e., clear zone) are the target
locations for this objective. Typically, the pole crashes are spread along the corridor and
there is not a single pole or cluster of poles that are in greater need of mitigation than the
rest. See Appendix 4 for an example of one state's approach to relocating utilities to improve
roadside safety.
Strategy 16.2 C1: Place Utilities Underground (P)
General Description
This strategy involves removing the utility poles and placing the utilities underground. If
the roadside exhibits a suitable recovery area, then this strategy could have a sizeable effect.
However, in many cases, there are other objects within the recovery area or there are other
roadside hazards present that may reduce the strategy’s effectiveness. If the poles are used
to support streetlights, in addition to utilities, removing the streetlight may reduce the
overall safety of the area. Jones and Baum (1980) found that 34 percent of urban utility poles
in their sample also had streetlights attached to them (for example, see Exhibit V-16). In
order to reduce the frequency and severity of utility pole crashes in such situations, one
could place utilities underground and install breakaway (slip-base or frangible) light poles
farther away from the road (behind the sidewalk) with luminaires on extension arms.
While placing utilities underground is a high-cost strategy, it is important to realize that
safety is not the only reason for doing this strategy. Many communities have programs for
placing utilities underground to improve aesthetics and possibly for security. Partnering
with these groups, safety engineers can help justify and prioritize the corridors where
utilities will be moved underground.
EXHIBIT V-16
Urban Location with Utility Poles Very Close to the Roadway and with Streetlights Attached to the Poles
EXHIBIT V-17
Strategy Attributes for Placing Utilities Underground (P)
| Attribute |
Description |
| Technical Attributes |
|
Target |
Corridors where poles are placed close to the road and there is a history of pole
crashes along the corridor or where there is a high possibility of pole crashes.
|
|
Expected Effectiveness |
The effectiveness of this strategy is difficult to determine because of issues such as the
location of other objects in the recovery area, the steepness of side slopes, and the net
effect of placing street lamps on separate luminaire poles or removing the streetlights
altogether.
With so many factors influencing crash severity and frequency, it is difficult to provide a
simple table for expected effectiveness. Agencies are referred to the FHWA computer
program ROADSIDE 5.0 of the Roadside Design Guide to complete economic analyses
of the existing and proposed conditions (removing poles, adding or not adding luminaire
poles, etc.). Economic analysis is necessary, to determine if the benefits of placing the
utilities underground outweigh the disadvantages. Although it is difficult to place a dollar
value on the aesthetic improvements, it is important that this benefit be reflected in
decision making. Therefore, a cost-effectiveness analysis is desired, in addition to a
cost-benefit analysis (See Section VI for further details).
|
|
Keys to Success |
A key to success is the condition of the recovery area, if the utilities are placed
underground and the poles are removed. If other high fixed objects are in the recovery
area, such as trees, buildings, and large plant boxes, or if there are steep side slopes,
then these hazards also should be mitigated.
Partnering with other organizations that are interested in placing utilities underground
can help the potential for success. However, the priorities for these groups may be
oriented more toward commercial and tourism interest than safety.
|
|
Potential Difficulties |
The high cost of the strategy is the primary difficulty.
Pole lines may carry many different utilities. If there is limited room in the underground
channel, it may not be possible to relocate all the utilities there.
|
|
Appropriate Measures and Data |
Process measures for a program would include the miles of utilities placed under
ground and the number of poles eliminated.
Impact measures include the number, severity, and rate of target crashes on locations
meeting the policy requirements. In this case, the target crashes are those crashes
within the project boundaries that strike poles, run off the road, or strike other fixed
objects.
|
|
Associated Needs |
None identified.
|
| Organizational and Institutional Attributes |
|
Organizational, Institutional, and Policy Issues |
DOTs should work with municipalities that are placing utilities underground for other
purposes to maximize the returns on limited funds. DOTs are working with local
agencies to establish cost-sharing policies for utility relocation.
Another institutional issue is maintenance. Restoration of power lines that are felled by
storms consumes resources and can be avoided if placed underground. However,
major maintenance underground can be burdensome and costly.
Another policy issue concerns DOT use of right-of-way to generate revenue
(e.g., placing cable and cell towers) within right-of-way.
|
|
Issues Affecting Implementation Time |
The time required to work with other agencies and to acquire the necessary funding, as
well as to complete construction, will result in this process requiring more than a year to
implement in most cases.
|
|
Costs Involved |
The costs are high and will vary depending on the complexities encountered along the
corridors.
|
|
Training and Other Personnel Needs |
None identified.
|
|
Legislative Needs |
None identified.
|
| Other Key Attributes |
|
None identified. |
Strategy 16.2 C2: Relocate Poles Along the Corridor Farther from
the Roadway and/or to Less Vulnerable Locations (P)
General Description
This strategy seeks to reduce pole crashes by locating the poles in less vulnerable locations
or by increasing the distance of the poles from the roadway. Fox et al. (1979) found that
poles at the curb were three times more likely to be struck than poles placed 10 feet from
the curb. Mak and Mason (1980) also found that pole crashes were overrepresented within
10 feet of the roadway. Zegeer and Parker (1983) developed a model using nearly
10,000 utility pole crashes in four states. This predictive model related the number of pole
crashes as a function of the average offset from the travel lane, the average daily traffic,
and pole density. When poles closer than 10 feet from the roadway were relocated to
points beyond 10 feet, it was found that the crash reduction was greater than for poles that
originally were located beyond 10 feet from the road and that were subsequently farther
removed.
Strategy Attributes
Strategy 16.2 A2 focused upon a single pole, or very few poles, at a specific location, such as
the outside of a curve or the end of a lane drop. Strategy 16.2 C2 focuses on longer sections
of roadway where many poles are involved. This strategy's attributes are the same as for
Strategy 16.2 A2, except that the cost will be considerably higher since it affects more poles.
Exhibit V-9A shows the crash reduction factors from the Zegeer and Cynecki (1984) data for
relocating a line of poles farther from the roadway along two-lane rural highways with
shoulders and no curbs.
Strategy 16.2 C3: Decrease the Number of Poles Along the Corridor (P)
General Description
This strategy consists of reducing the number of poles on the roadside by increasing the pole
spacing, placing poles on one side of the street only, or jointly using the poles (i.e., placing
multiple utility services on the same pole). The strategy is to reduce pole density along the
corridor. Jones and Baum (1980) found that pole density was the factor with the highest
correlation to pole crashes. The Zegeer and Parker (1983) model also includes pole density as
a variable in predicting the number of pole crashes.
The spacing between utility poles differs, depending upon the type of utility and the general
practices of the specific company. As poles are placed farther apart, the openings that will
allow a vehicle to pass through without striking a pole get larger. Exhibit V-18 demonstrates
the concept. As pole “A” is moved farther from the pole next to the vehicle, then the opening
(lightly shaded area) increases. If there is space between the poles and behind the poles as a
suitable recovery area, then the larger spacing allows a vehicle more space to recover.
Another way to reduce the pole density along a corridor is to have poles located only on one
side of the road. If the pole spacing can be maintained the same by placing multiple utility
services on the same pole, then this strategy should reduce the overall pole density by half.
However, the side of the roadway where the poles remain would not be expected to realize a
safety improvement since the conditions on that side remain the same.
Exhibit V-19 shows the strategy attributes for decreasing the number of poles along the
corridor. Exhibit V-20 shows a nomograph that relates the expected number of pole crashes
per mile per year to the average daily traffic, the pole density, and the average pole offset
from the roadway. The nomograph is based on the following equation that Zegeer and
Parker (1983) estimated:
| ACC / MI / YR= |
9.84x10-5(ADT)+0.0345(DEN)
(OFF)0.6 |
-0.04 |
EXHIBIT V-18
Schematic Showing How Increasing the Pole Spacing Provides Large Areas for Errant Vehicles to Pass through without Striking a Pole
The example in the nomograph shows a road with an ADT of 10,000 vehicles per day, a pole
density of 60 poles per mile, and an average pole offset of 5 feet. The expected number of
crashes is 1.15 pole crashes per mile per year. If the pole density is reduced by half by
placing all utilities on one side of the highway, then the expected number of crashes is
reduced to 0.75 pole crashes per mile per year (a 35-percent reduction). If the pole offset was
increased to 15 feet, rather than reducing the pole density, then the predicted number of
crashes reduces to 0.6 pole crashes per mile per year (a 48-percent reduction). However, the
better option would be to reduce the pole density AND increase the offset. The crash
reduction in this case would be a 65-percent reduction to approximately 0.4 pole crashes
per mile per year. This nomograph only predicts the number of pole crashes and does not
determine the number of ROR crashes or other fixed-object crashes.
EXHIBIT V-19
Strategy Attributes for Decreasing the Number of Poles Along the Corridor (P)
| Attribute |
Description |
| Technical Attributes |
|
Target |
Poles along a corridor where the pole density contributes to the frequency of pole
crashes.
|
|
Expected Effectiveness |
See Exhibit V-20 to derive an estimate of the number of pole crashes predicted, based
upon the average daily traffic, the pole density and the average pole offset from the
traveled way. To calculate the pole crash reduction, find the estimate for the current
conditions and the proposed conditions.
There may be an increase in the number of ROR crashes. Jones and Baum found that
ROR crashes generally had a lower severity than pole crashes. The authors show that
injury and fatal crashes comprised approximately 51 percent of pole crashes compared
with 29 percent of the ROR crashes. Although not quantified, the increase in ROR
crashes may also be offset more by an increase in the number of errant vehicles that
recover and never are reported as a crash.
|
|
Keys to Success |
The key to success is that there are no additional hazards along the roadway where
decreasing pole density will only allow vehicles to strike other fixed objects. The
program should not reduce the number and severity of pole crashes by transferring the
problem to other non-pole objects.
|
|
Potential Difficulties |
Increasing the pole spacing or placing all the utilities on one side of the road may
require using larger poles. Larger poles may cause an increase in the severity of the
crashes involving the remaining poles.
Reducing the number of poles may require the cooperation of utility companies, which
may be resistant to relocation of their utilities and sharing of poles.
|
|
Appropriate Measures and Data |
Process measures for a program would include the number of miles of roadway where
the pole density was reduced, the change in pole density for the specific corridors, the
number of poles eliminated, and the cost to complete the project.
Impact measures include the number, severity, and rate of target crashes. In this case,
the target crashes include all ROR crashes, fixed-object crashes, and any crashes
striking poles at the specific site. The impact should consider the severity of the target
crashes to determine that there was a safety improvement and not a problem transferal.
|
|
Associated Needs |
None identified.
|
| Organizational and Institutional Attributes |
|
Organizational, Institutional, and Policy Issues |
A number of issues may arise that will require cooperative effort to arrive at a
satisfactory resolution. These include responsibility for pole maintenance, roles and
responsibilities of the involved parties when problems occur, and leasing or payment
rights. Involvement of legal departments will be necessary to work out arrangements.
|
|
Issues Affecting Implementation Time |
The cost of the projects and the required coordination to relocate the services with
multiple utility companies may affect the implementation time.
|
|
Costs Involved |
It will be costly to relocate the services carried on the poles, remove the poles, and
possibly use larger and/or stronger poles. However, economic analyses may show that
it is a worthy investment. The cost may be offset if the application of the strategy is in
conjunction with a roadway project where the utilities would be required to relocate in
any case.
|
|
Training and Other Personnel Needs |
None identified.
|
|
Legislative Needs |
None identified.
|
| Other Key Attributes |
|
None identified. |
EXHIBIT V-20
Nomograph to Determine the Number of Pole Crashes Per Mile Per Year Based upon the Average Daily Traffic, Pole Density, and Average Pole Offset
Source: Zegeer and Parker (1983)
Key References
Alberson, D. C., and D. L. Ivey. “Improved Breakaway Utility Pole, AD-IV.” Transportation
Research Record 1468, Transportation Research Board. 1994. pp. 84–94.
American Association of State Highway and Transportation Officials (AASHTO), Roadside
Design Guide, Washington, D.C. 2002.
Fox, J. C., M. C. Good, and P. M. Joubert. Collisions with Utility Poles—A Summary Report.
University of Melbourne. Commonwealth Department of Transport. February 1979.
General Estimates System (GES). National Highway Traffic Safety Administration, National
Center for Statistics and Analysis, 1999.
http://www-nrd.nhtsa.dot.gov/departments/nrd-30/ncsa/ges.html.
Ivey, Don L., and King K. Mak. “Recommended Guidelines for New Utility Installations.”
Invited presentation to the Symposium on Safety in the Clear Zone and Utility Installations,
Committee on Utilities. Transportation Research Board. June 25, 1989.
Ivey, D. L., and J. R. Morgan. Safer Timber Utility Poles, Volume I—Summary Report, Federal
Highway Administration, Report No. FHWA/RD-86/154, September 1986.
Ivey, D. L., and C. P. Scott. Utilities and Roadside Safety, State-of-the-Art Report 9. Prepared by
the Utility Safety Task Force, Committee on Utilities (A2A07), Transportation Research
Board, 2004.
Jones, I. S., and A. S. Baum. An Analysis of the Urban Utility Pole Problem. Calspan Field
Services, Inc. Federal Highway Administration, Report No. FHWA-RD-79-117.
December 1980.
Mak, K. K., and R. L. Mason. “Accident Analysis-Breakaway and Non-Breakaway Poles
Including Sign and Light Standards Along Highways.” Prepared for Department of
Transportation, National Highway Traffic Safety Administration, and Federal Highway
Administration. Volume II: Technical Report, Report No. DOT-HS-805-605,
August 1980.
O’Day, J. Identification of Sites with a High Risk of Run-Off-Road Accidents. University of
Michigan, Highway Safety Research Institute. Report No. UM-HSRI-79-39. Ann
Arbor, Michigan. 1979.
Washington State Department of Transportation (WSDOT). Utilities Accommodation Policy—
M 22-86, Olympia, Washington. April 2002.
http://www.wsdot.wa.gov/fasc/EngineeringPublications/manuals/Final%20UAP.pdf
Washington State Department of Transportation (WSDOT). Utility Manual. Olympia, Washington.
September 1992.
http://www.wsdot.wa.gov/fasc/EngineeringPublications/Manuals/UtilitiesManual.pdf.
Zegeer, Charles V., and Michael J. Cynecki. Selection of Cost-Effective Countermeasures for Utility
Pole Accidents: Users Manual, Federal Highway Administration, Report No. FHWAIP-
84-13, July 1984.
Zegeer, C. V., and M. R. Parker, Cost-Effectiveness of Countermeasures for Utility Pole Accidents,
Federal Highway Administration, Report No. FHWA/RD-83/064, January 1983.
Zegeer, Charles V., and Martin R. Parker, Jr. “Effect of Traffic and Roadway Features on
Utility Pole Accidents.” Transportation Research Record 970, Transportation Research
Board. 1984. pp. 65–76.
|