Reducing speeds & reaching your destination without fear of death
Screengrab from a America Walks & Safe Routes to School presentation: Slowing Drivers Down
Why does a community need to live with increased risks so someone can race to stop sign or red light? Slowing us down when we are driving needs to be a primary goal every-time a community re-constructs a neighborhood street.
America Walks’ report, “Why We’re Stuck at High Speed, and What We’re Going to Do About It” (PDF) is recommended reading for neighborhood groups, parents, and traffic engineers concerned about public safety in our public rights of way. In it the three types of speed, as seen by traffic engineers is described, all of which we have discussed here from time to time.
- Operating Speed – observed by reviewing how fast we are actually comfortable driving on a street. If we are comfortable at 10 over, that may be the operating speed. The infamous “85th percentile” relates to the operating speed.
- Design Speed – traffic engineers typically design streets to accommodate speeding, rather than limit it. If the street is a 25-mph zone, it could be designed to “forgive” 35 to 40-mph. Some places, it may be argued that a street is designed to encourage 10-15 over.
- Posted Speed- pretty much the least important of the three because it is ignored so often. Speeds signs do very little to impact driver behavior and lack of enforcement compounds the problem. It takes a special circumstance for someone to get pulled over for going 35-mph in a 25 zone–as we can see above, with huge consequences.
America Walks continues in the report to describe the 4 Ways to slow us down, all of which require systematic approach building from other steps. Basically, the goal is to change Driver Behavior and this is best done by changing the design of the street. This was the primary focus of the Division Street steering committee in Traverse City and needs to be for almost every street where there are traffic complaints. If you change the context of any particular corridor with real traffic calming measures and street-scaping and you will reduce the wide gap in actual and desired speeds. After those measures, under the current system, a community may then have a better chance of reducing posted speeds, but even there, America Walks is recommending that the laws/systems governing speed need to be changed.
A twenty is plenty campaign (Walk-Sf) has had success in the state of California, where it is now possible to set speed limits next to schools at 15-mph. In Oregon, they have passed laws allowing for more local control in setting speed limits (B-Portland). This allows local communities to respond to each context and needs.
For many years we have valued high-speeds as the goal to designing our roadways. It is becoming apparent that this is costing us in real dollars, efficiency, and loss of community. High-speeds are only one aspect of mobility; being able to actually reach your destination without a fatal injury is quite another.
…More to come.