A Model for Setting Credible Speed Limits in Urban Areas

This article describes how setting speed limits is essential for ensuring appropriate traffic speeds and improving road safety in urban areas. The model used in this article is based on eight key parameters whose cumulative effects significantly affect the 85th percentile speed by setting speed limits from 25 to 43 mph by increments of 6 mph. The Highway Safety Code of Quebec, Canada permits municipalities to adopt a by-law allowing them to change a speed limit on their network without obtaining approval from the Quebec Ministry of Transport. The model for setting speed limits was designed to be a decision-support tool. It was developed to set a credible speed limit according to roadway features and the roadway environment and the research shows that some natural conditions are conducive to different speed limits.