An overview of speed model study under different types of facilities in Malaysian roadway system

The present paper reviewed past studies related to speed model studies and the measured traffic parameters used by other researchers. The purpose of the paper is to discover the relationships between speeds with the differences in roadway condition & characteristics, traffic composition, driver behaviour and to propose a research gap related to the future study of Malaysian road conditions. Fundamental relationships were observed over different parameters and were found to be significantly different. However, under uninterrupted flow facilities, using free-flow speed as a prediction for highway capacity analysis and determining the level-of-service (LOS), the time headway threshold, and the speed of observations at certain flow rates must be carefully studied to represent the free-flow speed in ideal conditions. The paper review helps the authors find research gaps for an in-depth investigation of the free-flow speed on Malaysian highways or expressways. Hence, the finding from the paper reviewed will be used in a future research study on developing a free-flow speed model based on the basic section of roadway in Malaysia.