Investigation on the Traffic Current Delay in the Weaving Sections Type A.

The weaving sections are developed due to meeting of two or more traffic currents passing through highways. Increasing the risk of accidents due to speed changes and maneuvering motions of vehicles as well as development of delay in freeways are amongst the issues related to weaving sections. In this research first of all the Dutch, HCM and FRESIM Methods for modeling of the weaving areas were studied. Comparing the HCM and DUTCH codes of practice shows that Dutch Model is not thoroughly mathematical and on the other side, taking into account the numerous limiting assumptions in this method, the HCM methodology was selected as the optimal method, and the travel time and delay time for various scenarios were investigated according to the volume of traffic currents, the length of weaving areas, and the percentage of the heavy vehicles. On the other hand by studying and knowing the FRESIM software and its relevant parameters the weaving area was modeled and calibrated. Then the outputs of simulation method and HCM method were compared. Results showed that despite the ability of simulation method to calculate the delays in the upper parts (reduced acceleration) and lower parts (increased acceleration), the simulation method software usually calculates less delay compared to HCM and from low to high volumes, the delay time shows a growth between %59 and %205. The trend of the increased delay in HCM is linear but the delay results by simulation method shows that in the medium volumes this trend is linear and in low and high volumes the change content is reduced. It was also concluded the despite taking into account the personal cars equivalent in the weaving areas parallel to freeway areas by HCM, this rate is different in FRESIM and its influence on the increased delay in higher volumes is higher.