Switching Fleet to CNG Was Carefully Weighed Decision for DART

Posted on July 17, 2014 by Gary Thomas - Also by this author

Switching our bus fleet to compressed natural gas from liquefied natural gas and diesel was a carefully weighed decision at DART (Dallas Area Rapid Transit). But in the end, it was a no-brainer: go with the fuel source that will promote clean air while saving taxpayers $120 million in fuel costs over the next 10 years.  

It wasn’t something we took lightly. As a taxpayer-supported agency, it’s contingent on us to examine every option we have, and to balance cost-effectiveness with other factors such as service quality and environmental impact.

To that end, we evaluated many technologies, including “clean diesel” (which didn’t offer significant greenhouse gas or fuel-cost reduction), and diesel/electric hybrid buses (which were expensive to purchase).  

In the end, we decided to migrate our bus fleet — some 650 buses — to clean-burning, compressed natural gas (CNG). Although CNG vehicles cost more than diesel vehicles, the fuel to run them saves $1.50 to $2 per gallon. This immediate cost reduction translates into major savings over the life of a vehicle.

But it isn’t just as simple as pulling up to a different pump and filling the tank. There are a lot of “moving parts” to be accounted for – not least of all, the complex procurement of hundreds of CNG-powered buses.

Additionally, we had to design and install a network of filling stations to keep those buses running. In this, we partnered with Clean Energy, which designs and builds CNG stations all over the country.


Now that the new buses have been on the streets awhile, we can see that the benefits extend beyond saving tax dollars and doing our part for clean air. Customers appreciate that the engines are quieter — and since the exhaust is cleaner, even nearby non-riders can be thankful for the reduction in fumes. Riders also have given us positive feedback about the new buses’ comfort. Meanwhile, DART’s bus drivers have told us they will never miss the days of going home smelling like diesel.  

But make no mistake, for transit authorities like ours moving to natural gas pays off in a big way. In fact, as a result of transitioning our bus fleet to CNG, DART will realize fuel savings of roughly $120 million over the course of the next 10 years. Clean Energy co-founder and long-time Dallas resident T. Boone Pickens says, “The public-private partnership of DART and Clean Energy is saving millions of dollars” for DART’s cities, and he’s right.

At DART, we’re used to getting attention for our light-rail system. But the bus system is the backbone of our transit network — we offer 120 bus routes, and serve roughly 250,000 riders on any given weekday. Improvements in bus service impact a greater number of people than any other mode. All told, DART transports the people of Dallas and surrounding cities more than 39 million miles a year — the equivalent of more than 80 round trips to the moon.

The DART story should ring familiar to those who, like me, have called the Dallas area home for many years. The DART Service Area of 13 cities has a way of rising to challenges, and of embracing big-picture solutions. The very existence of DART is one such example. And our agency isn’t just thinking about how to reduce costs, enhance the customer experience and improve the environment for this year or the next — we’re a forward-thinking agency determined to improve the quality of life in the Dallas area for generations to come. It’s a privilege to serve this great region — and no matter how far we’ve come, at DART we’re always just getting started. Kind of like the region we are proud to serve.  

Gary Thomas is the president and executive director of Dallas Area Rapid Transit (DART).

View comments or post a comment on this story. (4 Comments)

Post a Comment

Post Comment

Comments (4)

Please sign in or register to .    Close