Effect of traffic signs on accidents (Case study: Qazvin-Karaj freeway)

Goal: 

Among the different kinds of traffic equipment, traffic signs have a great impact on guiding and choosing the route of drivers. But which signs have the greatest impact on accidents varies depending on the road conditions. Research was needed to investigate the relationship between accidents and the lack of any kind of traffic signs. Given that signage is an inexpensive solution to increase safety, if safety can be increased by installing signs on a rout, it would be the best option to increase safety.

In this research, by field survey of Qazvin-Karaj freeway rout, deficiencies of traffic signs including : mandatory signs, deterrent signs, and warning signs and control cameras on the map of Qazvin-Karaj freeway rout were identified using Arc GIS software. Then, using the traffic statistics of this rout, the relationship between the number of accidents and the lack of traffic signs was investigated.

There is a significant relationship between the lack of warning signs and fatal accidents, but no relationship was observed between the lack of mandatory and deterrent signs and accidents. In other words, wherever there is a shortage of warning signs, the number of accidents is higher than in other places.

It can be expected that on roads where there is a safety problem, as a cheap and fast solution, traffic agencies will pay more attention to install warning signs and traffic police should closely monitor the correct installation of these signs.