U.S. Department of Transportation
Federal Highway Administration
1200 New Jersey Avenue, SE
Washington, DC 20590
It is important to evaluate intersection safety treatments after installation to determine their effectiveness. The effort that goes into conducting the assessment will help guide future decisions regarding intersection countermeasures.
A record of crash histories, if available, and countermeasure installations forms the foundation for assessing how well implemented strategies have performed. It is important to keep a current list of installed intersection countermeasures with documented "when/where/why" information. Periodic assessments will provide the necessary information to make informed decisions on whether each countermeasure contributed to an increase in safety, whether the countermeasure could or should be installed at other locations, and which factors may have contributed to the strategy's success.
To perform the assessment it is necessary to collect the required information for a period of time after strategies were deployed at the intersection. The time period varies, but should be no less than one full year (with 3 years preferred). The information required may consist of public input and complaints, police reports, and observations from maintenance crews. The most important information is crash data before and after implementation.
It is important to keep the list of strategy installations up to date since it will serve as a record of countermeasure history. By using this type of system, assessment dates can be scheduled to review the crashes and other pertinent information at intersections where treatments have been installed (see Table 4).
Action: Develop a spreadsheet to track future safety project installations and record 3 years of "before" crash information at those locations.
|Intersection||Specific Location||Type of Countermeasure Installed||Date Installed||Date Removed (If Appl.)||Comments||3 Years Prior to Installation||1 Year After Installation|
|Number of Public Comments||Number of Crashes||Number of Near Misses||Number of Public Comments||Number of Crashes||Number of Near Misses|
|Middlebrook Pike and Waples Mill Road||Waples Mill – West Approach||STOP Sign||12/19/2009||Sign was old and faded||0||0||0|
|Rt 123 and Fox Mill Road||Fox Mill Road – South Approach||Stop Bars||7/9/2008||5||0||1||2||0||0|
|Route 657 and Glade Drive||Route 657 – East Approach||Traffic Island at Stop Approach||6/4/2008||2||2||3||0||0||2|
|Route 657 and Clifton Road||Clifton Run – North Approach||Added Left-turn Lane||8/8/2007||4||1||3||1||0||0|