Speed Limit Review Survey

September 9, 2015

Oak Bay, in cooperation with ICBC, is undertaking a review of speed limits in the Municipality. The study results from a concern that the large number of different speed zones throughout Oak Bay might be confusing and potentially unsafe. The objective of the study is to obtain a rational process for setting speed limits that has been validated by research and practice in North America and around the world.

The Prudent Driver

One of the ideas behind management of speed is the idea that most drivers are reasonable and competent. Since the 1930’s this was the predominant way that speed limits were determined. A common practice is to measure actual speeds and determine the speed driven by a large majority of the population. For example, this chart shows speeds driven on Estevan Avenue, a quiet residential street and Lansdowne Road, an arterial road. Most drivers on Estevan Avenue drive at 32 kph or less while 85% of drivers on Lansdowne Road were recorded at 46 kph. Both roads have speed limits of 50 kph.

Prudent drivers graph

Oak bay street image

On this narrow street with parking and a curve, the 85th percentile is driving at 32kph.

Oak bay street image

On this wider street with good visibility and no parking, the 85th percentile is driving at 46kph.


Another important measurement of speed is pace. This is an indicator of the difference in speed on a street. Roads are safest when everyone is going the same speed as this minimizes passing and conflict. This chart shows speeds on two streets. Speeds are more consistent on Henderson Road and one would therefore expect fewer crashes.

Pace of traffic graph


Another important statistic is compliance. This is the percentage of drivers going at the speed limit or less. Compliance will generally be good when drivers believe that the posted speed limit is reasonable. Compliance can be improved temporarily by enforcement; however, most municipalities cannot afford high levels of enforcement on a continuing basis. This chart shows compliance on some streets in Oak Bay. This data supports findings of research that most drivers do not pay attention to posted speed limits, but drive at a speed that they feel is reasonable.

Prudent drivers graph

Send us your feedback

To send us your feedback, please complete the speed limit survey here.

If you do not want to use the survey, but want to send us feedback please email speedlimit@oakbay.ca