Geometric standards of highways and investigation of roadsafety: The example of Şırnak City Center

The most preferred type of transportation in Turkey is highway transportation. Excessive usage of highways causes an increase in the number of vehicles, hence, heavier traffic occurs. Heavier traffic causes traffic accidents. In Turkey throughout the last decade, approximately 50 thousand people died due to traffic accidents. In case of increased road safety, number of traffic accidents and, consequently, number of people who died in those accidents will decrease. According to Turk Stat's data among the factors that lead to a traffic accident, road is almost neglected. However, when developed countries are examined accidents caused by the road factor has a high percentage. Figuring out the road related defects that cause an accident will also decrease the other factors which are displayed in the statistics. In this study, highway geometric standards and road safety were examined based on the city center of Şırnak province. Three road sections with the lowest geometric standards were determined from among the all roads that were examined. Projects regarding the road sections were provided from the relevant institutions. From the road sections which were determined on the project, data such as project speed, transition curve, horizontal curve radius, horizontal curve length, superelevation, vertical curve length, and slope were obtained. A field study was conducted to determine if the project values and application values match or not. For the sections determined during the field study, current map purchases regarding the roads were being made. After the purchase of current maps, comparison in between the map values and the project values were being made. If the data was to be different, then the current values were accepted to be true. Obtained values were being compared with the geometric standards table. The mountainous section in the geometric standards table was taken into consideration. After determining the geometric standards of the determined sections, data regarding the traffic accidents which occurred in the abovementioned sections were obtained from the relevant institutions. The relationship between the occurrence form of the traffic accidents and geometric standards was examined. Key Words: geometric standards, traffic accidents, Şırnak, occurrence form of an accident.