Tim Engstrom, Pothole Prairie

It was good to read about an advancement in the technology for traffic signals in the Sept. 9 edition of the Albert Lea Tribune.

The Minnesota Department of Transportation unveiled a design that minimizes unnecessary waiting for motorists — and improves safety. The new stoplight was installed in Woodbury at the interchange of Interstate 94 and Minnesota Highway 95.

But there was one quotation in the story that stuck out. It was from Jerry Kotzenmacher, MnDOT senior engineering specialist: “This is the biggest change in traffic signal design and operation in the past 40 years.”

Holy moly, I thought right away. No wonder cars get such awful gas mileage in the city. Few, perhaps very few, traffic engineers are trying to change the way we move automobiles.

I immediate thought about my daily experience with the light at Main Street and First Avenue in Albert Lea. I meet that traffic signal going to work and coming home. That makes four times on the days I go home for lunch. I also might meet that signal in the other direction once in a while if I need to go from downtown to Nelson’s Marketplace, City Arena or a place on the west end.

Usually, though, I am on First Avenue and need to cross Main Street.

I have no complaints about the traffic signal’s functionality. It works as it is intended. Sometimes, some other cars have triggered the green and I get to enjoy a clean ride across Main. Other times, I meet a red and wait for the detector in the roadbed to detect me, then I go.

But a lot of times, this is what I see while waiting on First and looking both ways at Main:

There is a viaduct to the left and one to the right. A group of automobiles will be coming down a viaduct. Some get through, but the light turns yellow. One, two or three of the cars in the back of that pack brake for the red, losing all that downhill momentum.

That costs a lot of gas to go up the next viaduct. Plus, stopping while going downhill is hard on brakes.

With all the technology available today, why cannot traffic engineers create a signal that detects the traffic coming, rather than merely the cars entering the intersection?

Think about it. Traffic signals are supposed to keep automobiles grouped, not divide them up. If the light would have just let those one, two or three cars get through the intersection, there was a nice break in the Main Street flow. That’s when it is the right time to let First Avenue drivers go.

In other words, engineer to be more human. If there had been a police officer directing the traffic, that’s when he or she would have switched to let the other way go.

And it doesn’t seem like it would be that difficult to do.

The road engineers today have three main types of stoplights.

Timers are the most well-known.

Some use an inductive loop detector in the road — you often can see sawcuts in the road; it works like a metal detector. When your vehicle is detected, it actuates the lights. Sometimes, the length of the green light depends on how many autos pass over the detector. Many are three seconds more for every additional vehicle.

The third kind is video detection. Drivers notice a little telescope-looking device on the overhanging arm that holds the traffic lights. It is a camera fixed on the same spot in the road, usually near the white bar on the road where drivers are supposed to stop their cars. It is watching for a change of contrast. (Some early versions used to have a hard time in downpours or on foggy days.)

There is a fourth method I should not neglect. It is a technician in an office controlling the lights with a computer. The most well-known use of this method is on Oscar night in Hollywood. It’s how Los Angeles makes sure the limousines don’t all show up at once, don’t tie up traffic, don’t become some long convoy and do show up in the proper order. It is the most impressive display of stoplight manipulation on the globe.

OK, but forget that human method and the timer method and consider the other two methods for the sake of this point:

Why not put a detector up the road a bit, too? Maybe 150, 200 or 300 feet? For the amount of gas saved and wear and tear on automobiles saved, it probably would be worth it.

Sure, the reasonable argument against it is that the cars could just pull off the road on a street or business after being detected and not actually intend to go through the intersection.

But there are many intersections in this world — as the drivers of the cars coming down the viaducts know — where they cannot turn off or where very few turn off.

A little video camera, placed 200 feet up the viaduct, could see oncoming cars and tell the traffic signal the following: Hey, you dumb microchip, there are a couple of cars still coming westward down the viaduct. Wait just one second more, just one, that’s all, and they won’t have to stomp on their brakes to meet your illogical programming demands.

Engineers in many fields — stadiums, golf courses, office buildings, college campuses — have made great strides in thinking about how people want to move, rather than forcing them to move. Think Target Field compared to the Metrodome. In other words, design to be more human.

Doing that would bring great strides to the slow-progressing field of traffic signal design and operation.

Tribune Managing Editor Tim Engstrom’s column appears every other Tuesday.