Monday, September 8, 2008

That's Fundraising, Not Law Enforcement

There's an article in today's paper about the photo-red cameras being installed at three intersections in Spokane. This is particularly irksome to me. Spokane will pay $4600 a month for each camera and expects to net $190,000 a year. There's no mention of the number of accidents at each intersection. No mention of the expected reduction of accidents.

From what I've seen the success of photo-red cameras in other cities is always based on the dollar. If the city has to start paying for the cameras then the program is a failure and the cameras have to go. Also, and studies vary on this, the number of accidents aren't reduced so much as the type of accidents change. Drivers approaching a photo-red intersection are more likely to slam on the brakes resulting in getting hit from behind. So you can see that running a red light is not the only driver behavior involved, but it is the only behavior being addressed by the installation of photo-red cameras.

In other locales I've seen countdown timers for pedestrian crosswalks. The light changes from the white "Walk" to the amber "Don't Walk" and a timer starts counting down. Pedestrians see exactly how many seconds they have before the light changes and they can judge if they can make it across in time or should stop and wait. I think it's worth a try to display a countdown when the light turns yellow so drivers know how much time they have before it's red.

The Federal Highway Administration specifies all manner of traffic signs, lights, markings, etc. in the Manual on Uniform Traffic Control Devices.

Section 4D.10 Yellow Change and Red Clearance Intervals

A yellow signal indication shall be displayed following every CIRCULAR GREEN or GREEN ARROW signal indication.

The exclusive function of the yellow change interval shall be to warn traffic of an impending change in the right-of-way assignment.

The duration of a yellow change interval shall be predetermined.

A yellow change interval should have a duration of approximately 3 to 6 seconds. The longer intervals should be reserved for use on approaches with higher speeds.

The yellow change interval may be followed by a red clearance interval to provide additional time before conflicting traffic movements, including pedestrians, are released.

Three to six seconds. (If we only had five or six seconds on a bicycle, eh?) If the city were truly interested in reducing accidents, they might try increasing the length of the yellow light by a second or two and/or extending the time all directions have a red light. What is the goal here? Safe and efficient traffic flow or finding a way to add to the public coffers?

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