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Have Red Light Speed Cameras Saved Lives in Virginia?

Today on the Streetsblog Network, we've got a post from The WashCycle [1] about speeding, new red light cameras and a reduction in fatalities in Montgomery County, VA. Police there report that "a 2008 study of 11 camera locations found a 25 percent reduction in crashes on the roads where the speed cameras were located." Deaths have gone to 9 from 19 over a the same period last year. While the WashCycle cautions against reading too much into a relatively small amount of data, they also say the cameras have likely been effective. They also report on some novel citizen objections to the technology:

136414178_b9bb1f3508_m.jpgPhoto by Michael Patrick [2] via Flickr.
It is reasonable to assume that the cameras should get some credit -- if not the lion's share. As Prof. Steven Dutch [3] puts it, "Correlation doesn't prove causation when there is no plausible link between two phenomena, or when there is some more plausible cause. But if there is a plausible link, then correlation is very strong evidence for causation."

I've heard several arguments against speed cameras; such as privacy issues, not being able to face your accuser, manipulation of the data or circumstances to increase violations and, thus, revenue. But this is a new one:

"'I am against the speed cameras. No. 1, I don't think they pick up one of the major hazards on our roadways in Montgomery County right now -- bicyclists,' resident Reardon Sullivan told the Montgomery County Council."

Really? Bicyclists? Not drunk drivers [4]? Not inattentive drivers? Especially since we're talking about speed cameras (not red light cameras) -- and it is very difficult for cyclists to speed.

More from around the network: The National Journal [5] asks the experts what difference an 18-month delay in the transpo bill would actually make; World Streets [6] talks about scientific methods for reducing driving; and The Overhead Wire [7] looks at transit-oriented development in a down economy.