I really feel that's too fast. Dr. Paul Dietze, an ophthalmologist who lives at 1825 W. 12th St., said the largely residential street posed other safety problems. For one thing, he said, it has no sidewalks and a 35 mph limit would increase the danger to pedestrians. Also, he said, for much of the street, postal workers only deliver to boxes on the north side so residents have to cross the street daily to get their mail. Raising the speed limit to 35 would only make that more dangerous, Dietze said.
Accidents occurring at higher speeds increase the rates of severe injury and death.
In some cases, where careful before and after studies have been made, it has been shown that accident rates have been reduced by raising a speed limit to realistic levels. The 85th percentile, experts say. If the 85th percentile is 35 mph, it means that 85 percent of the drivers on a particular stretch of road drive that speed or slower. The city's recent traffic study of 12th Street between Westridge Drive and Washington Avenue showed the 85th-percentile speed ranged between 33.6 and 36.5 mph. The 85th percentile is the standard used by traffic engineering authorities nationwide, Wacker said.