Run-Off-Road Collisions

Index of Strategies by Implementation Timeframe and Relative Cost

Exhibit IV-1 provides a classification of strategies according to the expected timeframe and relative cost for this emphasis area. In several cases, the implementation time will be dependent upon such factors as the agency's procedures, the length of roadway involved, the need for additional right-of-way, and the need to follow environmental impact processes. The range of costs may also vary for some of these strategies because of many of the same factors. Placement in the table below is meant to reflect the most common expected application of the strategy.


Classification of Strategies According to Expected Timeframe and Relative Cost

Relative Cost to
Implement and Operate

Timeframe for Implementation




Moderate to High


Short (<1 year)

15.1 A1—Install rumble strips


15.1 A3—Install midlane rumble strips


15.1 A4—Provide enhanced delineation of sharp curves


15.1 A6—Provide enhanced pavement markings


15.1 B3—Remove/relocate objects in hazardous locationsa


Medium (1­2 (years)

15.1 A7—Provide skid-resistant pavements


15.1 A8—Eliminate shoulder drop-offb


15.1 B1—Provide shoulder treatmentsc or four-lane sections at key locations*


15.1 B2—Design safer slopes and ditches


15.1 C1—Improve roadside hardware


15.1 C2—Improve barrier and attenuation systems


Long (>2 years)

15.1 A5—Improve horizontal curve geometryd

a Removal/relocation of some objects (e.g., bridge abutments and drainage structures) can be costly, depending upon the object. It is assumed here, however, that most objects will be small appurtenances.

b The action could be done in a short timeframe. However, it is assumed to be done at little extra cost as part of a regular repaving program.

c The classification of shoulder treatments and safer slopes and ditches as moderate-cost or moderate-to-high-cost treatments assumes that no additionalright-of-way is needed. If right-of-way is needed, the cost could be high and the time required would be long.
d Although the AASHTO Strategic Highway Safety Plan is focused upon relatively low-cost, short-term strategies, there are some higher-cost strategies such as curve flattening that have potential for such significant effectiveness that they have been included. Curve flattening would primarily be applicable in rehabilitation, resurfacing, and restoration (3R) and reconstruction projects that have been programmed outside the context of the AASHTO plan initiative.