Our friends in politics say they're keeping us safe from the horrors of distracted driving.

Statistics don't lie, do they? And they tell us that when you're not paying attention on the road, people can be hurt or killed in crashes.

So the campaign against distracted driving is a good thing.

Our lawmakers have made it illegal to use handheld cellphones while driving, and texting while driving is a no-brainer.

But there's another kind of distraction that happens in those split seconds when you're pulling up to a traffic light and it turns yellow. Just then you're probably distracted by the feeling of the government's hand right on your behind.

Right on your pants, where you keep your wallet.

And that's the problem with the so-called red-light cameras.

You see them in Chicago, and in many other cities and towns. Go through a red light, and your car will be electronically ticketed. Sometimes you'll pay $100.

The mayors and council leaders sell the red-light cameras as safety cameras, insisting that they're designed to cut down on crashes, including the right-angle collisions known as "T-bone" accidents.

But that's not the real reason for the red-light cameras. The real reason is revenue. Since the red-light cameras were instituted in 2003, City Hall has hauled in some $400 million in revenue. And that chunk of revenue didn't require cops writing tickets or tax dollars to pay the cops' salaries and benefits.

Red-light cameras are about squeezing the behinds of drivers, and it's been painful. You can't fight a red-light camera ticket. There's your car in the photo. So you pay.

So let's be honest about this. Let's stop calling them "red-light cameras." Why not call them "squeeze-the-behind cameras" or "buttock revenue enhancers."

Personally, I think "buttock revenue enhancers" is rather poetic. The buttocks of the people get squeezed, the revenue is enhanced, and City Hall smiles.

Naturally, as Mayor Rahmfather's policy geeks read the words "buttock revenue enhancers," they will take umbrage with this column and clench their fists in rage and write angry letters to my boss.

His people will note, and properly so, that the buttock revenue enhancers have indeed cut down on T-Bone car crashes in every city they've been tried.

But there's another feature of the cameras. Once drivers get hit with a few tickets, an amazing thing happens: They're driving, the light turns yellow, they've become conditioned like Pavlov's dog, and they slam on the brakes to avoid a ticket.

The car screeches to a halt. And whew, they don't get a ticket. But they get something else: rear-ended.

"I just had a four-car rear-ender," Mike the Cop told me the other day. "Four cars. Why? Because of the cameras."

Study after study shows that rear-enders increase with the installation of buttock-revenue-enhancing red-light cameras. A 2005 study by the Federal Highway Administration showed there was only a "moderate" safety impact when the squeeze-your-behind cameras were installed. And then, only if they were carefully placed by traffic experts.

The University of North Carolina's Highway Safety Research Center notes that crashes from drivers running red lights are a serious problem. But it also cites statistics showing that the average number of rear-end crashes went up 15 percent after red-light cameras were installed. Hence, Mike the Cop's anecdote about the four-rear-ender is supported by dispassionate research.

More cameras mean fewer T-bone crashes and more rear-end collisions. In other words, the safety issue cuts both ways. But the revenue issue goes in a single clear direction — from your wallet to City Hall's pocket. So it's not about the safety. It's about the cash.

I'm not going to get into a bickering match with the Emanuel administration on traffic stats. Last year, the mayor became incensed with Tribune reporters who questioned him, saying there had been a 60 percent decrease in traffic deaths near Chicago's red-light cameras.

"You guys have continued to repeat wrong information because it doesn't fit your storyline," Emanuel said back then, angrily thrusting his "study" at a reporter.

I shouldn't say he actually "thrusted," since I wasn't there. But when he talks like that, he's capable of thrusting. The main thing is that he challenged the Tribune to analyze his report.

Guess what? The Tribune analyzed the report. And after it was analyzed, a City Hall official was compelled to admit that the mayoral claim of a 60 percent reduction in fatalities was based only on an informal analysis.

"Study is a bit of a term of art," said Scott Kubly, managing deputy commissioner in the Chicago Department of Transportation.

Hmmm.

In Chicago you can drive like a crazy man, running countless red lights. As long as you pay, City Hall won't tell the secretary of state. So your dangerous driving will be just between you and the Rahmfather.

Don't worry. He won't tell. Just remember to pay.

It's not about safety. It's not about the color red or yellow. It's about the green.

That's what buttock-revenue-enhancing red-light cameras are all about. They squeeze and they squeeze and they get what they want. The money.

And that's as distracting as City Hall's hand on your behind.

jskass@tribune.com

Twitter @John_Kass