Are Speed Limit Signs a Cost-Effective Strategy to Manage Urban Speeds and Implement 20MPH “Living Streets”?

According to the 20′s Plenty campaign, 20mph speed limits for all residential areas throughout Europe have emerged as the key recommendation of the EU Transport and Tourism Committee on improving road safety in Europe. This announcement was made by European Parliament on June 21, 2011.

Studies have proven that 20 MPH speed zones have a dramatic impact on reducing the level of pedestrian injury. Slower street speeds are also associated with more social connections, a stronger sense of community, higher property values, more accessible walking and better conditions for bicycling. Unfortunately, citywide traffic calming projects, such as those created in many European cities over the past 30 years, can take many years or even decades to roll out across an entire city. So how can cities move forward on creating these zones in a more cost-effective way?

A British review suggests that, when combined with community involvement, even just posting lower speed limits can be an effective method to shave a few miles per hour off the speed of local vehicular traffic:

“Where signs-only schemes are used, small speed reductions and accident savings can be achieved if associated publicity and enforcement campaigns are also used.”