POTENTIAL CONFLICTS

Using this strategy alone likely will not have much of a lasting effect at creating a safer environment for pedestrians, bicyclists, and drivers. Motorists drive speeds they feel comfortable and safe with depending on the design of the road. Ultimately, posting a lowered speed limit sign will not have a lasting effect that keeps speeding at bay. Instead, the likelihood of traveled speeds remaining the same without other action is greater than if the physical design of the road was changed in some manner.

It is important to note that drastically changing the speed limits more than five miles per hour could cause more harm than do good. Engineers set speed limits on roads that make sense for the road and surrounding context itself. There are different classifications of roadways which determine the likelihood of a higher or lower posted speed limit – often determined by the amount of access points and chances of pedestrians and bicyclists being present. Arterial roads have higher speed limits and fewer access points (on and off ramps to a highway), collector roads which can have higher speeds but more access points (country roads), and local roads which have lower speed limits but high access points (neighborhood streets with driveways and downtowns). Speed limits realistically should only be set at five miles per hour (mph) below what is recommended by an engineer. It is possible that decreasing a posted speed limit more than the recommended five mph might lead to an increase in traffic crashes.

Cost

Low-cost