Comparison of Operational Performance Before and After Improvement: Case Study at Pengkalan Weld, Pulau Pinang

Delay Study is to evaluate the quality of traffic movement along a route and to determine the level of service at a study area. This study can be used to compare and evaluate operational conditions before and after roadway or when intersection improvements have been made. The objective of this study is to compare before and after the improvement of intersection into roundabout in term of delay time and level of service. This study only focused at the intersection which had massive congestion along Pengkalan Weld road. There are two intersections which experience a massive traffic jam during morning peak hour. The worst traffic jam occurs at the intersection connected to Gat Jalan Magazine (Case study area 1) especially for the vehicle coming from south of Pengkalan Weld to north bound. This traffic jam occurs because of the long cycle of traffic signal. The second worst traffic jam occours at the intersection connected to Gat Lebuh Chulia (Case study area 2). It is a 4 leg-intersections without a traffic signal. The traffic jam occur at the particular section because there is no traffic light which could guide the road users to cross that conflict area. The minor road which is from Gat Lebuh Chulia has disrupted the major road which is the Pengkalan Weld road. Thus, the motivation of current research is to evaluate these intersections into the space sharing intersection or also known as roundabout. To achieve this purpose, the simulation VISSIM model had been created. VISSIM software was also used to analyse the field data by using the average speed method. The field data was collected during AM peak hour since it has the highest traffic volume per hour compare to PM peak and off peak. From the result both method (vissim and field data) produced slightly the same result in delay time. This means that VISSIM simulation is acceptable to be used. Second model was develop in order to design roundabout by using the VISSIM simulation. As conclusion, by using Vissim simulation it was found that the improvement from intersection to roundabout had minimized delay time and improvement of LOS by 97.8% for Case study area 1 and 75.6% for Case study area 2.