Night time driving perception and visual performance under adverse and clear weather conditions while maneuvering on urban roadway curve

Development of models for predicting the 85th percentile speed is widely used and developed by most countries. However, proper speed distribution analysis is vital in ensuring the model is usable and represent the traffic condition. In respond to that, the focus of this study is to identify the distribution of traffic among various conditions. Two approaches of data collection were used. RealCountTM for collection of continuous speed data and spot speed study for 85th percentile speed at 20m approaching the curve, at the beginning of curve and at the middle of curve. From the analysis conducted on these data, several findings were discovered. It was found that there is significant difference to the vehicle speed travelled at night and during wet pavement condition. The speed distribution is further analyzed by comparing the means at 20 m approaching the curve, at the beginning of curve, at the middle of curve and at the end of curve.