There's a reason lead-footed folks hate speed cameras. They work. Right here in Maryland, they're already motivating drivers to take it a little easier on the gas.

That's the conclusion of the Insurance Institute for Highway Safety's recent study of the speed camera program implemented by Montgomery County last year -- the first of its kind in Maryland.

The institute's researchers found that in residential areas and school zones equipped with cameras and warning signs, the percentage of drivers exceeding the speed limit by 10 mph or more declined by two-thirds.

If translated to your neighborhood, that would mean that instead of three out of every 10 drivers blowing by your child or grandchild's school at 10 mph or more over the limit, only one would do so. And that one would get a well-deserved ticket.

The General Assembly is considering a bill this year that would permit other jurisdictions in Maryland to introduce similar programs in school zones and residential areas. The same legislation, which is backed by the O'Malley administration, would also allow the use of speed cameras in highway work zones.

One would hope that the legislators voting on the bill would take the time to read the institute's Montgomery County study. Truly diligent lawmakers might also want to check out a companion report on a speed camera pilot program in Scottsdale, Ariz. They can find both at www.iihs.org.

The institute noted that speeding was a known factor in about one-third of fatal crashes in the United States in 2006. Those crashes resulted in about 13,500 fatalities -- more than four times the toll of the Sept. 11 attacks.

The study noted that 23 percent of those fatalities -- about 3,100 -- occurred on streets posted with speed limits of 35 mph or less. My rough calculation puts Maryland's share of that toll at about 45 lives a year.

Montgomery County's speed camera program limits the cameras to streets in school zones or with speed limits of 35 mph or less. To get a ticket, a car has to be going at least 10 mph over the limit. The car's owner is subject to a fine of $40 but no points because the cameras identify only the vehicle, not the driver. (The pending legislation would raise the fine to $75 and allow cameras in areas with speed limits up to 45 mph.)

The institute deployed its own cameras before the county's were installed and afterward to measure changes in driver behavior.

The report's findings indicate there's a big difference in results between a real camera and a bluff. Where both signs and cameras were installed, the average speed decreased twice as much as in locations where signs were put up but no cameras. It seems word gets around.

Do the cameras influence driver behavior beyond the streets where they're deployed? Judging by the study, a little but not much. At nearby 40-mph zones, there was a 16 percent reduction in drivers exceeding the limit by 10 mph.

So if you really want to cut into speeding on major highways, don't count on cameras on Leafy Lane to do the job.

The institute also conducted a survey of Montgomery County drivers that showed 74 percent considered speeding on residential streets a problem.

After six months of enforcement, 60 percent of the county drivers were aware that cameras were being used for speed enforcement. Young drivers ages 18 to 34 were especially aware of them. Among those who were aware of the cameras, 57 percent said they had slowed down on residential streets.

At the end of the six-month period, supporters of the speed cameras outnumbered their opponents 2-1: 62 percent versus 31 percent. The survey also suggests that lawmakers have been unnecessarily timid in restricting the use of the cameras to residential streets. It found the same level of support for deploying them on arterial streets.

A second study by the institute of a pilot speed camera program in Scottsdale suggests that Maryland is missing an opportunity for real safety improvements by limiting the program to residential areas.

The Arizona program posted cameras on the interstate-like Loop 101, a road with a 65 mph speed limit. The study found the cameras reduced the percentage of drivers going more than 75 mph from 15 percent to 1 to 2 percent. The institute's survey found that during the program, Scottsdale drivers supported it, 77 percent to 20 percent.

The Maryland bill (SB269/HB364) is more of a cautious expansion of speed camera enforcement than a bold step forward in highway safety. It gives the would-be speeder every possible break -- including starting the program with 12 months in which only warnings could be issued. Hearings are tomorrow in the Senate and Wednesday in the House.

Given the timidity of lawmakers in taking strict steps to punish traffic violations -- and the vocal minority of drivers who believe they have a constitutional right to get away with stuff -- it's probably wise to take a measured approach.

But the institute's study should give legislators confidence that they can do the right thing -- saving lives in the process -- without paying a price at the polls.

POSTSCRIPT: Perhaps, after the horrific crash that killed eight in Prince George's County on Saturday, the governor will be emboldened to propose a broader use of cameras to crack down on known drag-racing venues.

michael.dresser@baltsun.com