Implementation Process: Appendix G-3

Example Table of Crash Attributes vs. Candidate Strategies for Crashes Occurring at Unsignalized Intersections

Exhibit 1 is an index of candidate strategies for addressing crashes occurring at unsignalized intersections. The strategies listed are those that are covered in the Guide for the AASHTO Strategic Highway Safety Plan addressing crashes at unsignalized.

In many cases, roadway inventory data may be available as an additional source to help relate problems to candidate strategies. Where the scope of the analysis is limited to a relatively small portion of the road system, field studies can provide needed details to help select the appropriate strategies to consider. Other sources of data are sometimes available, as well, which can help in the analysis. Details of the problem identification process are covered in the discussion of Step 1 of the Model Implementation Process.

Many of the strategies listed in the guide for crashes at unsignalized intersections are potentially applicable to several of the crash factors. Even where this is not the case, it may occur that more than one crash factor will be identified as significantly associated with the problem. In these cases, the sum of strategies associated with each of the factors, as listed in Exhibit 1, should be considered.

Exhibit 1. Strategies vs Crash Attributes.

Objectives	Strategies	Crash Type (Combination of MMUCC¹ Elements C6 and C8)
		Manner of Collision where First Harmful Event is Collision with Another Motor Vehicle					First Harmful Event in Crashes Involving Single-Motor Vehicle
		Angle	Head-on	Rear-end	Sideswipe, same direction	Sideswipe, opposite direction	Collision with bicycle	Collision with parked vehicle	Collision with pedes-trian	Over-turned	Run-off-road
17.1 A - Improve Management of Access near Unsignalized Intersections	17.1 A1 - Implement driveway closures/relocations
	17.1 A2 - Implement driveway turn restrictions
17.1 B - Reduce the Frequency and Severity of Intersection Conflicts through Geometric Design Improvements	17.1 B1 - Provide left-turn lanes at intersections
	17.1 B2 - Provide longer left-turn lanes at intersections
	17.1 B3 - Provide offset left-turn lanes at intersections
	17.1 B4 - Provide bypass lanes on shoulders at T-intersections
	17.1 B5 - Provide left-turn acceleration lanes at divided highway intersections
	17.1 B6 - Provide right-turn lanes at intersections
	17.1 B7 - Provide longer right-turn lanes at intersections
	17.1 B8 - Provide offset right-turn lanes at intersections
	17.1 B9 - Provide right-turn acceleration lanes at intersections
	17.1 B10 - Provide full-width paved shoulders in intersection areas
	17.1 B11 - Restrict or eliminate turning maneuvers by signing
	17.1 B12 - Restrict or eliminate turning maneuvers by providing channelization or closing median openings
	17.1 B13 - Close or relocate "high risk" intersections
	17.1 B14 - Convert four-legged intersections to two T-intersections
	17.1 B15 - Convert offset T-intersections to four-legged intersections
	17.1 B16 - Realign intersection approaches to reduce or eliminate intersection skew
	17.1 B17 - Use indirect left-turn treatments to minimize conflicts at divided highway intersections
	17.1 B18 - Improve pedestrian and bicycle facilities to reduce conflicts between motorists and non-motorists
17.1 C - Improve Sight Distance at Unsignalized Intersections	17.1 C1 - Clear sight triangles on stop- or yield-controlled approaches to intersections
	17.1 C2 - Clear sight triangles in the medians of divided highways near intersections
	17.1 C3 - Change horizontal and/or vertical alignment of approaches to provide more sight distance
	17.1 C4 - Eliminate parking that restricts sight distance
17.1 D - Improve Availability of Gaps in Traffic and Assist Drivers in Judging Gap Sizes at Unsignalized Intersections	17.1 D1 - Provide an automated real-time system to inform drivers of the suitability of available gaps for making turning and crossing maneuvers
	17.1 D2 - Provide roadside markers or pavement markings to assist drivers in judging the suitability of available gaps for making turning and crossing maneuvers
	17.1 D3 - Re-time adjacent signals to create gaps at stop-controlled intersections
17.1 E - Improve Driver Awareness of Intersections as Viewed from the Intersection Approach	17.1 E1 - Improve visibility of intersections by providing enhanced signing and delineation
	17.1 E2 - Improve visibility of the intersection by providing lighting
	17.1 E3 - Install splitter islands on the minor-road approach to an intersection
	17.1E4 - Provide a stop bar (or provide a wider stop bar) on minor-road approaches
	17.1 E5 - Install larger regulatory and warning signs at intersections
	17.1 E6 - Call attention to the intersection by installing rumble strips on intersection approaches
	17.1 E7 - Provide dashed markings (extended left edgelines) to define the median opening at divided highway intersections
	17.1 E8 - Provide supplementary STOP signs mounted over the roadway
	17.1E9 - Provide pavement markings with supplementary messages, such as STOP AHEAD
	17.1 E10 - Provide improved maintenance of STOP signs
	17.1 E11 - Install flashing beacons at stop-controlled intersections
17.1 F - Choose Appropriate Intersection Traffic Control to Minimize Crash Frequency and Severity	17.1 F1 - Avoid signalizing through roads
	17.1 F2 - Provide all-way stop-control at appropriate intersections
	17.1 F3 - Provide roundabouts at appropriate locations
17.1 G - Improve Driver Compliance with Traffic Control Devices and Traffic Laws at Intersections	17.1 G1 - Provide targeted enforcement to reduce STOP sign violations
	17.1 G2 - Provide targeted public information and education on safety problems at specific intersections
17.1 H - Reduce Operating Speeds on Specific Intersection Approaches	17.1 H1 - Provide targeted speed enforcement
	17.1 H2 - Provide traffic calming on intersection approaches through a combination of geometrics and traffic control devices
	17.1 H3 Post appropriate speed limit on intersection approaches
17.1 I - Guide Motorists More Effectively through Complex Intersections	17.1. I1 - Provide turn path markings
	17.1 I2 - Provide a double yellow centerline at the median opening of a divided highway intersection
	17.1 I3 - Provide lane assignment signing or marking

¹ Final Model Minimum Uniform Crash Criteria (MMUCC), established by NHTSA and FHWA in August of 1998 (http://www.nhtsa.dot.gov/people/perform/trafrecords/pages/mmucc/mmucc_documents.htm)