Development of operating speed model based on urban arterial design standard traffic condition

Road consistency modeling is used to detect any inconsistencies in road alignment, particularly horizontal and vertical alignments. Unusual features of road geometries or inconsistencies can result in unsafe driving experience due to carelessness in handling of vehicles. To help minimize the risk of accidents at curve, 85th percentile speed model is needed for Malaysian scenario to ensure its´ road consistency. The current technique of identifying design speed is prone to produce inconsistencies in road design. This is because the geometric elements determined from the identified design speed are based on minimum values and although it is recommended to adopt higher values for road construction, no maximum value is set. This type of design guidelines in practice will tend to produce inconsistency in operating speed along the road roadway alignment. With that in mind, this research aims to develop models for the purpose of validating consistencies of urban road specifically horizontal alignment. As for the methodology, several methods were adopted such as spot speed study, VBOX and loop detector. After several analysis were conducted one model with R-Sq value of 74.5% is proposed as a starting basis for Malaysia.