Evaluation of Operating Speed at Multilane Highway Along Jalan Meru: Case Study of Reliability of Posted Speed Limit

Operating speed and traffic volume data are collected on different sections of four lanes and six lane roads at three different points along Jalan Meru, Klang. The objective of this study is to identify the vehicular speed at different points which conforms to the geometric design of the road. The speed data compiled is analyzed using the percentile approach, V85, V95, and V15 and describing the condition of traffic compared to posted speed limit along the road. Speed data are analyzed by generating a regression equation using advanced statistical software in order to estimate the precision of the data taken. Hence, graphs illustrate a trend and correlation between speeds at 85th percentile, 95th percentile and 15th percentile with traffic flow rate are plotted. Based on data, the operating speed of V85 at location A and B are lower than the posted speed limit since the speeds taken were interrupted by control device at the upstream and downstream of the traffic stream. While at location C, the operating speed of V85 is higher than the posted speed limit and is not affected by any constraint. The trends on the graph of V85, V95, and V15 versus vehicles flow rate show that the speed is decreasing as the road capacity increases.