Safety Effectiveness of Selected Treatments at Urban Signalized Intersections Academic Article uri icon

abstract

  • This study conducted a beforeafter evaluation by means of the empirical Bayes methodology for four types of treatments at signalized intersections with data from Winston-Salem, North Carolina. The results indicated that changing to protected left-turn phasing from permissive or permissiveprotected phasing could lead to a virtual elimination of left-turn crashes but other crashes, which were likely to be less severe, could increase. Conversion from nighttime flashback to regular phasing seemed effective in reducing nighttime crashes. Replacing 8-in. signal heads with 12-in. heads seemed effective in reducing right-angle crashes, but this measure could increase other, less-severe crashes. Adding another red-signal lens to an existing one or changing from permissive to permissiveprotected left-turn phasing did not seem particularly effective in reducing crashes, but these results were not definitive because they were based on a limited number of sites. Further research using data from other jurisdictions is needed, so that more definitive conclusions can be made about the safety effectiveness of these treatments.

published proceedings

  • TRANSPORTATION RESEARCH RECORD

author list (cited authors)

  • Srinivasan, R., Council, F., Lyon, C., Gross, F., Lefler, N., & Persaud, B.

citation count

  • 20

complete list of authors

  • Srinivasan, Raghavan||Council, Forrest||Lyon, Craig||Gross, Frank||Lefler, Nancy||Persaud, Bhagwant

publication date

  • January 2008