Don’t want a ticket? Don’t speed

What’s so hard to understand about speed limit enforcement?

Every driver knows about speed limits. There are signs posted at regular intervals on roads and highways across the state. The written driver’s license test requires test-takers to know about maximum speeds in various Iowa traffic venues: interstates, two-lane highways, residential streets, business districts.

There are even signs for minimum speed limits on some busy interstate stretches.

No driver should be surprised to be stopped for going well above the maximum speed limit.

Multiple studies show speed kills: the faster the vehicle travels, the longer the distance it takes to stop it. That’s why the law sets limits.

Law officers customarily give drivers some cushion. A friend told me he heard from one state trooper that “at eight you’re great, at nine you’re mine,” referencing the speed beyond the legal limit at which you’re likely to be stopped.

Des Moines police say publicly that the speed cameras on I-235, the Des Moines freeway, don’t write tickets on vehicles going below 71 mph in the freeway’s 60 mph zone.

That’s a very generous 11 mph of grace.

Full disclosure: I generally set my cruise control at five miles an hour above the speed limit. Even though I’m therefore breaking the law, I’ve never been stopped for speeding at that rate. I certainly could be, and I realize I have no legitimate legal excuse for traveling in excess of the limit.

I’ve been stopped a few times for speeding, but in those cases I’ve been clocked at more than five miles per hour above the limit. No defense and no argument from me. Usually I’ve received a warning rather than a ticket and fine.

So what’s all the fuss about speed cameras?

There are a few stretches of Iowa road where speeding seems to me to be the norm rather than the exception.

One is Interstate 80.

Another is Interstate 35 between Ames and Des Moines.

And another is Interstate 235, the Des Moines freeway.

The speed limit on the freeway is 60 mph outside of the 40 blocks or so closest to downtown, where it drops to 55. If you travel the freeway’s speed limit, or even five miles per hour above it, you’re much more likely to be passed than to do the passing.

There are controversial speed cameras near eastbound 56th Street on the freeway and at several other locations in Des Moines. For years there’s been a kerfuffle over them: Does the Iowa Department of Transportation have jurisdiction over them? Do they create more dangerous conditions than if they weren’t there? Are they simply a way for the city of Des Moines to generate revenue?

There’s no consensus on the subject in the Iowa Legislature. Sen. Brad Zaun of Urbandale for years has led the fight to outlaw the cameras, on I-235 and elsewhere. Sen. Tony Bisignano of Des Moines has championed leaving them in place.

The latest decision, handed down this summer by the Iowa Supreme Court, gives the city of Des Moines the power to decide whether to write tickets using speed cameras within its jurisdiction. That decision reversed a previous lower court ruling, and the city thereupon reactivated its ticket-issuing procedure.

The city had refrained from issuing tickets during the time the cameras were not allowed to do so, but had left them on and running. The data collected during that time showed the average speed on the freeway increased when no tickets were allowed from the cameras.

Some opponents of the cameras even argue that speed cameras are “unfair” — as though operating a motor vehicle is some kind of game or sport.

Des Moines police have an answer for the charge that the cameras are only a way for the city to enrich its treasury. They say the revenue from speed cameras allows the city to maintain an additional nine officers on the police force, thereby providing more security for the city’s residents.

The state legislature in its wisdom has significantly cut the state’s public safety budget, forcing a reduction in the number of state troopers.

Fewer troopers mean less enforcement of traffic laws and less safety on the state’s roads. Many municipalities have faced similar budget cuts in recent years.

Speed cameras provide a way to mitigate some of that loss.