GETTING THE HARDWARE AND THE SOFTWARE RIGHT.  It has long been a position of Cold Spring Shops that unsynchronized traffic lights waste fuel and illustrate the folly of technocratic solutions.  An Isthmus interview with Madison traffic engineer Brian Smith suggests the technocrats might be taking the easy way out.

There are centralized, computer-controlled, coordinated systems that are set up so lights "cascade" in sequence, occasionally allowing us to drive for several miles without encountering a single red light. (There's a system on Johnson Street that frustratingly uses this concept to prevent anyone from driving over 25 mph, but that's another story.)

That "frustratingly" highlights a tradeoff that will come to light subsequently. Timing traffic lights to reinforce the speed limit is on balance desirable.  What reader cannot identify a road along which the only way to make all the lights is to speed.  I remember getting angry on a stretch of a New Jersey highway that was posted 55, which I was obeying in my rental car, and getting held at each light, while the locals were maintaining 65 and making all of them.

There are systems in place, in a few cities abroad, where a computer senses circumstances on the ground and changes stoplight patterns and timing accordingly. That's the next step in traffic engineering. And the reason for all the gadgetry? It's not to mess you up. It has, well, a higher purpose.

"We want to minimize the number of stops and starts the vehicles have to do, which creates more pollution, more burning of gas and more crashes if cars are having to come to a stop when they're not expecting to," Smith says. "We try to set the lights to facilitate movements that we know will be coming."

Efficiency in a traffic system is unbelievably difficult to achieve. One car pulling to a stop at a detector loop somewhere on your trip to the mall can throw a wrench into your cascading green lights. Heavier traffic in one direction can mess up people going the other way. Pedestrians can push the walk light, offsetting any carefully constructed timeline engineers have programmed. A freight train passes through town. Accidents happen, or lightning strikes. Or Rhythm & Booms.

That detector loop problem is probably solvable. The loops are in use in DeKalb, and there are crossings where I wait for a very long time with no cross traffic coming for the detector to override the cycle.  Can it be that costly to concatenate the detector with the cascade so as to protect the sequencing?

Traffic engineers are public servants, and not all members of the public see things the same way.

Engineers adjust the timing of pedestrian lights to match the width of the road. They keep track of vehicle capacity, so when construction sends cars to a different road, they're ready for the increased flow. They figure out whether taking 10 seconds from a column of traffic's green light will wreck the commute of another column of traffic half a mile away. If a butterfly flaps its wings on Doty Street, the wind is felt on Old Sauk — or worse, on the other side of the Beltline, where in some parts of the city, intersections under the state's purview use a different kind of traffic signal controller. ("I've heard rumors they might switch to ours," Smith says.)

Engineers' carefully calibrated programs are sometimes scuttled by residents who want cars to stop at their lights even when intersections are empty — frustrating! — or by downtown business groups who want lights to favor pedestrians. If you enter the system from a side street in those areas, chances are you're going to hit the first signal and have to wait, even when there's nobody there, Smith says.

"There are times people call us yelling, using four-letter words and stuff, about how we should change it, but there's been some pressure by some neighborhood groups to have certain signals operate that way."

Perhaps those residents are bothered by speeding cars ... here lights timed to the speed limit will prove useful.  But giving pedestrians proper priority may be beyond any technocratic fix.