In this November 2013 file photo, lanes of Capital Beltway traffic snake through Tysons Corner. (Robert Thomson/The Washington Post)

When the final portion of the Capital Beltway opened 50 years ago this weekend, the idea of building wider highways to solve transportation problems was at its zenith. Over the next half-century, the D.C. region would add many more highways, but others would be canceled as we made different choices.

The biggest update in the Beltway design came in 2012, when the high-occupancy toll lanes opened. Now, the Virginia government is expanding the HOT lanes network to include 29 miles of Interstate 95/395 and is considering a project on Interstate 66 beyond the Beltway.

There’s general agreement among transportation planners and travelers that we want the existing highway network to be more efficient. How to achieve that is another matter.

Dear Dr. Gridlock:

Before construction of the HOT lanes, the intersection of I-66 and the Beltway was a major bottleneck. When coming eastbound on I-66, one had to enter the Beltway from the left, and many drivers then had several lanes to cross to get to Tysons Corner.

Merely eliminating that terrible merge opened up I-495 going north! Are the HOT lanes, per se, really necessary?

The regular lanes are still crowded, and the HOT lanes traffic is sparse. While a few fortunate drivers for whom the large tolls are not important can move along, the vast majority of drivers do not use these mostly empty lanes.

Shouldn’t the primary goal in the D.C. metropolitan area be to relieve traffic congestion, not just raise revenue?

I understand how difficult it is to get money for large projects, but the construction of the HOT lanes has eliminated the possibility of expanding the number of lanes for all traffic. Any relief is temporary, as it always is, because of continued development and population growth.

I am not in favor of converting I-66 HOV lanes to HOT lanes. The HOV lanes are now available for cars with only two people in them. My experience is that these lanes are well used, and converting to HOT lanes merely makes the lanes available to high-income drivers who want special treatment.

The only solution for the D.C. area is getting people out of their cars and making it easier to drive or otherwise get to transit, which means more, and cheaper, Metro and commuter bus parking; larger subsidies for buses and Metro, and a serious rethinking of road construction.

Instead of road widening as a first response, what can be done with better traffic light timing, correction of small local bottlenecks, additional incentives for carpools and van pools and encouragement of remote working for at least part of the week?

All of this would cost a lot of money, but would it be more or less expensive than billions for many miles of road widening and lane construction?

— Dennis Chamot, Burke

The letter packs in some sound observations and asks many of the right questions.

Let’s focus on one: Should our primary goal be to relieve traffic congestion? That’s a trick question. If you say yes, you’re destined for disappointment. We’re not going to relieve congestion in the foreseeable future. If we devote a lot of money and brain power to the problem, we’re going to make congestion less worse than it would have been if we had done nothing.

If you say yes, you are siding with advocates for big road projects. Most travelers in the region drive, and they’re going to keep on driving, even though we have one of the nation’s most extensive transit systems.

To have the greatest impact on traffic congestion — at least in the short-term — you want to make it easier for people to drive. Fix problem spots, like the I-66/
Beltway interchange. (Chamot is so right about that improvement.) You might also want to widen the Beltway through Bethesda, its worst bottleneck, and while you’re at it, build another Potomac River crossing to take pressure off the American Legion Bridge.

Less-spectacular efforts also would help, such as better traffic-light timing and the easing of small bottlenecks through reconstruction.

Expanding the transit system won’t provide as much congestion relief in the short run. The logic of supporting transit improvements for today’s commuters is to give them more travel options.

Any big effort, whether it’s HOT lanes or a new transit line, involves big bucks. The HOT lanes program has as much to do with raising money for projects as with managing traffic. Fixing the I-66/Beltway bottleneck wouldn’t have happened without financing from the 495 Express Lanes project.

The biggest change in U.S. transportation since the Beltway opened may be in the financing system rather than the projects.

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 .