This report contains a review and assessment of speed limits posted in speed zones on Provincial rural highways, and practices used by the Ministry of Transportation (MoT) to determine the appropriate speed limit. Municipal speed limits and speed limit setting practices are not within the scope of this study. Based on the results of the assessment, recommendations are offered to improve safety and traffic operations on Provincial roads through the application of speed limits and other speed management techniques. Speed zoning has been used for many years in British Columbia to influence motorist behavior. In general, speed zoning is the process of establishing a safe and reasonable speed limit on a highway segment. Speed limits are primarily set for safety reasons, i.e., to reach a balance between travel time and crash risk, and to provide a basis for enforcement of inappropriate speeding behavior. Maximum speed limits enhance safety by placing an upper limit on speed choice, and reduce the differences in vehicle speeds by drivers using the same road at the same time. Based on years of experience and observation, the following fundamental concepts have been used to establish realistic speed zones. The majority of motorists drive at a speed they consider reasonable, and safe for road, traffic, and environmental conditions. Posted limits which are set higher or lower than dictated by roadway and traffic conditions are ignored by the majority of motorists. The normally careful and competent actions of a reasonable person should be considered legal. A speed limit should be set so that the majority of motorists observe it voluntarily and enforcement can be directed to the minority of offenders. A driver’s choice of speed can impose risks on other road users. Crash severity increases with increasing speeds because in a collision, the amount of kinetic energy dissipated is proportional to the square of the velocity. Crashes, however, appear to depend less on speed and more on the variation in speeds. The likelihood of a crash occurring is significantly greater for motorists traveling at speed slower and faster than the mean speed of traffic. Maximum speed limits are set for ideal road, traffic, and environmental conditions. Establishing safe and realistic uniform speed zones is important because it invites public compliance by conforming to the behavior of the majority of motorists and provides a clear reminder to violators. It also assists the courts by providing a guide as to what constitutes a reasonable and prudent speed and reduces arbitrary enforcement and conviction tolerances. Furthermore, it ensures that the requirements and intent of Provincial and local laws and ordinances are met. (Author/publisher)
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