Use Traffic Conflicts Technique (TCT) to Evaluate Serious Intersections in Damascus

Traffic Conflict Technique TCT has a long history in traffic safety researches. Traffic accidents are now well known to generate a serious problem that exhausts enormous resources of the national economy either directly or indirectly. Because signalized intersections are potential black spot locations that may cause too many accident this research uses the traffic conflict techniques for analyzing accidents at signalized intersections. In this research, TCT was used at four-leg signalized intersections in Damascus to evaluate safety at these intersections. The relationship between conflicts and accidents was estimated and the results indicated that the conflicts and the accidents are related to each other by a linear regression. Results also showed that the correlation was unclear between conflicts and entry volumes at the intersections. Additionally, priority ranking of these intersections was developed based on risk index that depends on injury level.

Studying the saturation flow according to HCM2010 and comparing it with the field saturation flow on the signalized intersections (Case Study: Tartous City)

The evaluation of the capacity of signalized intersections is one of the most important parameter used in the planning, design, operation and management of urban street networks. The calculation of capacity depends on the estimation of the saturation flow of the signalized intersections. The highway Capacity Manual (HCM 2010) is used to estimate and analyze the saturation flow. This method is widely used in many countries around the world, including Syria. It reflects the local conditions in the United States of America; therefore it may not be suitable for use in our local conditions. This study includes estimation of the field saturation flow depending on the headways between the vehicles in the queues, and comparing the field results of the saturation flow with the values resulting from using the HCM. The study was conducted on three intersections in the Tartous city. The analysis was based on data collection using video. The final results confirmed that there is a clear difference between the field measurement of the saturation flow and computation value, Which confirms that it cannot be used for our local conditions.