Modeling Level of Service of Urban Roads Based on Travelers’ Perceptions

This research investigates and models the level of service for urban roads based on travelers’ perceptions. A video-based perception survey is utilized to collect the required perception data, in which the survey participants assessed the quality of operating conditions illustrated in the given video clips. The ratings stated by the study participants were statistically related to the corresponding traffic parameters associated with the video clips using a random-effects ordered probit modeling approach. The primary findings confirm that level of service was primarily dependent on average travel speed, as indicated by the significance of the measure of effectiveness known as the percent free-flow speed. Subsequently, a comprehensive exploratory analysis revealed that other traffic characteristics such as control delay, extra lanes, and proper medians also influenced the perception of service levels. Specific traveler characteristics like age, income and usage of particular vehicle classes also influenced the perception of the level of service on urban roads.