PREDICTED EFFECTIVENESS COUNTERMEASURE

Abstract

Improving road traffic safety has high effect to reduce the cost of traffic accidentand save the user of highway. Since 1985 the average stopped delay has been used asthe measure of service in signalized intersections analyses , on the other hand it isdifficult to evaluate the traffic safety in terms of change in number of traffic accident,because the traffic accidents accord has no reliable accident recorded ,while it not onlyreflect the number of accidents well, but also their nature ; traffic conflict technique isan efficient tool for analyses traffic safety. This study is aimed to developed traffic safety at 4 four- leg signalized intersectionsin Baghdad City. Regression analyses is performed to relate hourly traffic conflict andaverage stopped delay .Specific categories of countermeasures such as signalizationand geometric countermeasures are adopted. HCS 2000 software are adopt to determinethe average stopped delay before and after countermeasure implemented. The results show that the negative exponential model related hourly traffic conflictto average stopped delay and show a better explanation rather than linear model ,aswell as it is found that exponential model explains increasing variation (81.6 ) of totalhourly traffic conflict in relation with average stopped delay . The highest reduction innumber of traffic conflict after signalization countermeasures is 74.63% more than thehighest reduction after geometric countermeasures when it reduce by 58.07% . Thisstudy recommends to use traffic conflict technique as a tool to improve traffic safety byany proposed countermeasures.