Effectiveness of Countermeasures Simultaneous implementation in Black Spots (Case study: Malayer-Jokar axis)

Existence research for to evaluate the effectiveness of a series of Countermeasures in reduction crashes on the Malayer-Jokar axis in Hamadan province. In this axis, in 2015, a series of Countermeasures have been implemented during three months. To determine the effectiveness of the set of Countermeasures, Crashes data were used 19 months before and 19 months after the implementation of these Countermeasures. Due to its high efficiency in estimating the expected accidents without implementing Countermeasures and also eliminating the phenomenon of regression, the business method was used to average. The high accuracy of this method is due to the use of safety performance function (SPF) in order to logically estimate the frequency of crashes in the period before the Countermeasures. A crash prediction model was used using AASHTO (2010). Using this tool and predicting crashes before and after the implementation of Countermeasures, as well as the calculation of the expected number of crashes in the before and after periods, the effectiveness of safety was calculated. The results showed that the combination of these Countermeasures reduced the crashes by 4 percent. Although the significant assessment of this value showed that it is not significant at the 90 percent confidence level, the result is still valid, and this small amount of accident reduction, as the type of collisions observed in the after period has shown, is most likely due to the fact that Some Countermeasures have led to a reduction in certain types of crashes and an increase in other specific types.