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The Army Corps Of Engineers Approach To Traffic Control

Larry Landwehr

Mary and I left Wisconsin on November 8, 2000 to move to Guadalajara. We delayed until the 8th because we both wanted to vote in the presidential elections before leaving. We hitched our packed 4 by 8 foot trailer behind the car and headed south.

Everything went fine until we reached Dallas too late in the day to get a permit from the Mexican consulate to import our trailer-load of household goods into Mexico. We were stuck in Dallas for the weekend. Fortunately Mary had friends that recently moved there from California. We used our enforced idleness to chat, eat, and do some shopping - especially for more English language books.

One thing I couldn't help but notice was the traffic in Dallas. All the roads were congested. There were mile long backups. You could hardly get from point A to point B because of all the cars. It was similar to the situation that existed in Tampa, Florida when I had lived there. I’d avoid going out in the evenings because fighting the traffic just wasn't worth it.

Dallas is taking steps to handle its traffic. There is new road construction everywhere with monolithic columns of concrete looking like modern Stonehenges while they await new roadbeds. There are traffic cones and barrels all over. I joked that Dallas was where the state of Wisconsin stored its traffic cones during the winter when it didn't need them.

Maybe all this new road construction will solve Dallas' traffic problems, but I suspect it will only turn Dallas into a new Los Angeles where hour-long commutes to your job every morning are common and accepted.

Then I started thinking about Guadalajara, the city where Mary and I are going to live. Dallas and Guadalajara are both major cities, but I have never seen mile long backups in Guadalajara. I started wondering why this was so.

I think one reason is the pattern of how buildings are laid out. Dallas has zoning laws. Commercial buildings are grouped together. There seem to be a zillion strip malls in Dallas (all with the same franchised businesses). Dallas is "lumpy". Guadalajara, on the other hand, is mostly homogenized - the buildings are mixed together.

Another reason for the lack of traffic backups is the greater use of buses and taxis in Guadalajara. Taxis are cheap and buses are even cheaper. So there is less of a load on the roads of Guadalajara.

The different driving styles of Mexican and US drivers also makes a difference. The Mexican approach to driving is much more pragmatic than in the US. If something works, why not do it. Don't know which lane of traffic will move the fastest? Drive in two lanes at once. Got caught in the left hand lane at the intersection where you need to turn right? Just cut across the other lanes just before the light turns green. Are two marked lanes of traffic not enough? Start your own third lane - other drivers will quickly line up behind you.

Mexican traffic is very fluid. Lane markers are just a suggestion. Dealing with your first glorietta (a traffic circle or round-about) is a real interesting experience. The trick is to stay to the inside of the circle until just before your exit comes up. Then you start drifting to the outside in time to make your getaway. If you innocently try to stay to the outside the entire time, other drivers trying to make their exits will be angry to find you blocking their way - you are expected to exit at the next street if you are on the outside.

A glorietta is highly fluid with cars entering and exiting, cars moving to the outside as they revolve around the circle. If you don't follow the unofficial rules you create turbulence, which really screws things up. Mexicans are good drivers because they understand fluid driving and use it.

US drivers, on the other hand, are much more used to following official rules. In fact, they are often prevented from doing logical things. There are little crossover roads on US highways marked "authorized traffic only" which only police and slow moving road maintenance vehicles can use to turn around. I have more than once been caught in a traffic jam where the crossover road is blocked by a police car, preventing any cars from escaping the jam. They probably justify it by arguing safety concerns. But why not keep the crossover road open and use the police car and a few traffic cones to create a temporary merging lane for cars that want to turn around, thus relieving some of the pressure? Or even better, why not build Mexican "retornos"?

On Mexican highways there are retornos where you can legally and safely make a U-turn. It basically consists of an exit lane on the inner side of a dived highway, and a merging lane on the inner side of the other half of the divided highway. Did you miss a turnoff? No problem, just use the next retorno. Caught in a traffic jam? Just use the next retorno when you get to it.

Another reason for the much lower traffic congestion in Guadalajara is the greater use of one-way streets. This creates the problem of "you can't get there from here" until you get to know the streets, but once you learn the area you realize that they work. Finally, I think that modern divided highways draw traffic off of side streets. A kind of "if you build it, they will come" situation. People flock to the divided highways because they expect rapid, safe transportation. But once they enter the system, they find they have given up a significant amount of control. They are now channeled and controlled by concrete barriers and police cars. I refer to this phenomenon as "the army corps of engineers approach to traffic control".

The army corps of engineers turns wild untamed rivers into concrete lined ditches controlled by dams. Natural flood plains are converted into "useable" land where people can put up buildings. The trouble begins when unusual amounts of rain stress the system and it breaks down. Water breaks free and floods the old flood plains.

We have the same problem with divided highways. They are built to handle projected volumes of traffic, but they are not built with overflow mechanisms such as retornos that could relieve the pressure. The US could learn something from Mexico.

Published or Updated on: January 1, 2000 by Larry Landwehr © 2008
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