Tuesday, April 1st, 2014
[ Chuck Banas doesn't write that many blog posts, but when he does, they are money. Here's one he filed from Madison, Wisconsin during a CNU conference in 2011 - Aaron. ]
Let’s start with a specific issue: street design. The Congress doesn’t officially start until tomorrow, so I’ve used today to get to know a bit of downtown Madison and critique the design of the streets and public spaces. This didn’t stop me from trolling the online pages of The Buffalo News; during a break this afternoon I spied an article today about sidewalks and pedestrian safety. Author Bruce Andriatch merely scratches the surface of this important issue, falling short of addressing it properly.
But who’s to blame him? A design subtlety that is lost on most non-planners, including Buffalo News columnists, is that sidewalks are a necessary element for safe street design, but insufficient in themselves. If pedestrians are being endangered, the design speed of the road is usually the culprit. Many if not most roads in this country are intentionally designed for much higher speeds than the posted limit. A 30 mph speed-limit sign on a road designed for 50 or 60 mph is a futile—and sometimes fatal—exercise in wishful thinking.
Here are the sobering facts: at 30 mph, vehicle-pedestrian accidents are fatal in about 5% of cases; at 40 mph, fatalities are 90%. This is not to mention injuries, which can be devastating in their own right: incapacitating injuries are significantly less likely and less severe at slower speeds.
Therefore, the actual, effective solution involves “traffic-calming” the roadway so that drivers naturally move at slower, safer speeds. There are many methods to accomplish this, used in various combinations according to the specific situation. These include: fewer and/or narrower lanes, planting orderly rows of roadside trees, allowing curbside parking, using brick or other types of pavers for the road surface, curb bulb-outs, employing roundabouts instead of signalized intersections, smaller corner radii, etc.
Done properly, traffic throughput is still maintained, with less stop-and-go frustration for drivers, and much greater safety and civility for all users of the roadway, including pedestrians and bicyclists. For the vast majority of surface roads, there is simply no reason to design for a speed limit over 30 mph. Doing so seems careless and downright irresponsible, but this is the unfortunate norm for most highway departments.
This isn’t to say that traffic engineers are malicious—they’re just following a prescribed set of rules. The engineering standards that govern most roadway design were written in the mid-20th century, in the midst of a obsession with the automobile and the high-speed expressway. Higher design speeds were considered safer for cars and drivers. This myopic goal ignored any other users, as well as the physical context of the road itself. That the road might be part of a town or city neighborhood hardly entered into the equation. Under these standards, still in effect today, roads are too-often treated identically to expressways, designed only for the high-speed convenience and safety of cars. What happens beyond the curb or shoulder doesn’t matter.
The good news is that the rules are changing. The old standards, embodied mainly by the AASHTO highway design manuals, have been superseded by new tools and standards, most recently (and importantly) the ITE design manual Designing Walkable Urban Thoroughfares: A Context Sensitive Approach, adopted in 2010. Traffic engineers and citizens alike now have a sophisticated set of official standards with which to design roads that serve all users and all contexts.
Incidentally, on May 24, Transportation for America released a comprehensive report on pedestrian deaths. Dangerous by Design studies 47,000 pedestrian fatalities in the US from 2000-2009, mapping them on an interactive web page. Enter any location, and find out details on fatalities, thoroughfare type, etc. Check out pedestrian fatalities in your neighborhood; you may learn something about street design and safety in the place you live.
This post originally appeared in Joe the Planner on May 31, 2011.