The Association for Commuter Transportation (ACT) convened in Atlanta this week for its annual meeting, bringing together transportation professionals from across the U.S., Canada and several other countries. This event was my first opportunity to meet others outside the Atlanta region who work in the same field: “transportation demand management,” or TDM for short.

It’s tough to throw out TDM in casual conversation outside the 2008 ACT International Conference without getting blank stares …
“What do you do for a living?”
“I work in the transportation demand management industry.”
“Huh?”
… but TDM is a core concept for The Clean Air Campaign’s efforts to reduce traffic and improve air quality.

What is transportation demand management? TDM is related to the economic principle of supply and demand. It’s the notion that mobility can be improved by making better use of existing transportation infrastructure, instead of just adding more capacity.

Still scratching your head? Think of it this way: If you’ve ever been crawling along in traffic, you’ll agree metro Atlanta’s roadways are in high demand with too many cars competing for a limited supply of navigable space. So there are two possible remedies:
1. Increase the supply of roads by laying down more asphalt.
2. Decrease the demand for use of those roads by promoting alternatives to driving alone, like carpooling, vanpooling, bicycling, riding the Xpress Bus, teleworking or even compressing workweeks. Not only do these solutions fight off gridlock, they also help improve air quality, as 50% of all smog-forming emissions come from the tailpipes of cars.

TDM was borne out of the energy crisis of the 1970s, when every motorist wondered if the supply of oil could keep pace with the growing demands of an increasingly mobile nation. TDM provided immediate relief while car companies worked on developing more fuel-efficient vehicles and the government worked to develop more research for alternative energy.

Fast-forward to this decade and it might seem like déjà vu all over again. Nationwide, the question today is whether the supply of oil can keep pace with the simultaneous demands of several growing nations. And in many locales, including Atlanta, the question is how the supply of transportation infrastructure can keep pace with unprecedented demand stemming from population growth.

Fortunately, there is increasing demand for TDM solutions among employers, commuters and municipalities … and there is an increasing supply of bright TDM professionals who came together to share their wisdom at the 2008 ACT International Conference.

To borrow from the ACT Conference’s theme, “the road leads back to you.” So, how are you making smarter use of the transportation options available to you? Do you hop on MARTA to go the airport? Do you carpool to work? Do you walk to do simple errands? Tell us how you’re reducing demand … and your transportation footprint.