The Beltway express lanes, pleasing to some drivers and baffling to others, continue to be among the top topics for local travelers.

Dear Dr. Gridlock:

Tolls are supposed to be based on real-time traffic conditions. On Saturday, April 13, I traveled the complete route, north to south. The fee was $2.05 between 4:05 p.m. and 4:20 p.m. I have seen this fee listed as $1.85 at other times. I seriously question the real-time fees as the route was almost completely empty the entire way.

One car was a ways ahead of me, three passed me about midway and one was trailing me the whole way. My question is, how could $2.05 be the rate when there were effectively no users? The rate should have at least been the lower $1.85 I had observed more than once on different days and times.

This express lane idea is a poor substitute for HOV lanes, or better yet, local and express lanes.

— Tom Lewandowski, Herndon


The toll is controlled by a computer getting information about travel conditions from sensors along the route. Toll changes are supposed to reflect the level of congestion. The theory is a rising toll will limit congestion by discouraging the demand for the lanes.

Nobody in the control center has to eyeball the traffic and declare whether it’s 20 cents more congested than it was yesterday.

But the computer has to learn about the express lane drivers, just as drivers have to learn about the express lanes. They haven’t had enough experience with each other since the lanes opened in mid-November.

Pierce Coffee, director of marketing at Transurban, the company that operates the lanes, said the tolling system will get smarter the longer it’s in operation.

“We’re still definitely within that ramp-up period,” she said. “What this customer is probably seeing is two things at play. One is increasing traffic on the lanes, especially at interchanges like Jones Branch, Westpark and Lee Highway. The other is that our system is gathering information of how people are reacting to prices.”

Lewandowski described a day-to-day variation of 20 cents along the 14 miles of express lanes. That’s not much variation considering the variety of traffic conditions that might exist in that corridor.

Coffee gave an example that might better illustrate the toll fluctuation based on increasing traffic: 2 p.m. vs. 6 p.m. last Tuesday going from Jones Branch Drive in Tysons to the express lanes’ end near Springfield. The midday drive costs $1.70. The rush hour drive costs $4.20.

So, what’s the price point behind a driver’s decision to go express or take a chance on the regular lanes? Different people would react differently to that $2.50 swing on Tuesday afternoon. And the same person might react differently from one afternoon to the next, depending on whether the person had an appointment after work.

Those are among the things the computer must learn.

But this isn’t the whole story behind the tolls. You’re paying for a product, and that product is a reliable trip. You’re paying for the presence of extra safety crews to assist stranded motorists. You’re paying for new access points into the offices and shops of Tysons. You’re paying for the private partners who built the four new lanes to recover their investment.

There wouldn’t be four new lanes on the Beltway if Virginia had not found private partners to build and operate them.

Dr. Gridlock also appears Thursday in Local Living. Comments and questions are welcome and may be used in a column, along with the writer’s name and home community. Write Dr. Gridlock at The Washington Post, 1150 15th St. NW, Washington, D.C. 20071 or e-mail