The city of Spokane has wisely tapped the brakes before entering the brave new world (for us) of catching red-light-running drivers with cameras. Questions about the practice and the preferred vendor warrant caution.

The practice of photographing red-light violators and mailing them a fine has shown promise in other cities, but whether this technology reduces the number of crashes overall is uncertain. What is clearer is that the number of violations will probably drop.

Confused? We don’t blame you. As a 2005 review of red-light camera research by the Federal Highway Administration shows, all of the studies thus far have some fundamental flaws that preclude firm conclusions. For instance, cities that install cameras may also ramp up their public-information campaigns, add signage and make engineering changes, such as extending the time of yellow lights or changing the time intervals between red and green. Which of those worked? Which did not? Is there a spillover effect at intersections that don’t have the cameras?

What does seem clear is that all of those efforts combined do pay off in lessening the damage from right-angle crashes caused by red-light runners. While some studies show a corresponding increase in rear-end collisions, those do not offset the gains in reducing the more severe wrecks. In short, right-angle crashes hurt more and cost more.

Seattle installed four cameras at notorious intersections last summer. Thus far, 8,500 citations have been mailed out, but the number per month has declined. Officials have yet to draw conclusions on the program’s impact on collision totals.

Some critics say the cameras are merely cash cows, but that’s not borne out in studies. No city is generating unseemly sums. The chief benefits are changing dangerous driving behaviors and freeing up police officers for other duties. So, are the cameras worth it? Since the city’s contract calls for citations to cover the costs of the cameras, it wouldn’t appear there is much risk. But outcomes need to be measured carefully and shared with the public.

There were 106 crashes with injuries caused by red-light runners in Spokane last year, according to the Police Department. Let’s give this a try, but keep expectations reasonable. The benefits will probably be less than those touted by vendors.

Speaking of vendors, the city’s preferred choice has a controversial background. Affiliated Computer Services of Dallas is facing bribery allegations in Edmonton and has experienced equipment problems in Washington, D.C. Also, a chief financial officer resigned over irregularities related to stock options.

Like it or not, the public is going to be wary of this new program, so trust will be important in building support. Picking the wrong vendor would kill this effort for good. The city needs to proceed with caution.