Dear Dr. Gridlock:

There will probably be substantially more traffic flowing across the river bridges into Maryland once Virginia completes construction of its new, expanded lanes on the Capital Beltway. Virginia’s highway expansion is impressive.

Yet I’ve seen absolutely nothing to indicate where this new congestion is to go once it enters Maryland; a massive new bottleneck seems inevitable once cars cross the bridges. Am I the only one to observe that the Free State seems totally unprepared to absorb this new traffic?

— Charles S. Mack, Rockville

Whether or not Virginia’s projects wind up pushing more traffic across the river, Maryland will have to do something about the western side of the Beltway and nearby Interstate 270.

But I’m no longer certain that the key Virginia program, the high-occupancy toll lanes project on the Beltway, is going to send a lot more traffic across the American Legion Bridge into Maryland.

As the final year of construction on the HOT lanes approaches, officials at Transurban, the company that will operate them, talk in terms of managing the congestion on the Beltway rather than generating new trips. They look for commuters to use their toll lanes to go a few miles on days when drivers have a special need for a reliable trip. That scenario isn’t likely to have much effect one way or another on congestion north of the Legion Bridge.

“The majority of HOT lanes users will be traveling in Virginia,” Michelle Holland, a spokeswoman for Transurban, said about the market the company envisions.

Most HOT lanes users heading north in the morning are likely to exit between Interstate 66 and the Dulles Toll Road interchange. There will be three exits for Tysons Corner in that stretch.

Does the absence of a traffic surge mean Maryland should rest easy? No. The outer loop merge onto I-270 north is just awful at rush hours — morning and afternoon — and the skinny part of the inner loop through Bethesda is just ghastly in the afternoon.

The Maryland State Highway Administration is studying what to do about its portion of the Beltway. David Buck, a spokesman for the highway administration, said options under consideration include adding one express toll lane in each direction along the Beltway and building two such lanes in each direction along the narrow stretch between the I-270 spurs.

Studying is cheap, compared with building. Maryland has invested a lot in the Intercounty Connector and the Express Toll Lanes project north of Baltimore. It’s difficult to predict when the state could take on another major highway construction project.

But commuters are so selfish: They’re always asking if help could come within their lifetime.

Buck said the highway administration is looking at shorter-term options on the west side of the Beltway, such as adding acceleration and deceleration lanes at various points between the Legion Bridge and I-270 as well as at spots along I-270.

It sounds like small stuff, and it is, compared with a new highway or transit line. But these short-term improvements could ease knots of congestion.

Still, even those little improvements need fuller engineering studies and public reviews — a process that takes money and time. This is another reason Marylanders need to look seriously at raising the state gas tax.

Who’s right?

Dear Dr. Gridlock:

My understanding is that most people ride bicycles because they enjoy it and because it is good exercise and is good for the environment.

I have noticed a trend where bike trails intersect roads. Sometimes, bikers will expect cars to yield for them even though the cars have the right of way. This seems illogical.

If either the car or the bicycle has to yield, it makes much more sense for the bicycle to yield. If the car stops, it loses all of its momentum. This means that it will end up using more gas to get back up to speed and also emit more pollution. 

On the other hand, if the bicyclist yields, he or she will lose forward momentum and will have to use additional physical energy to get back up to speed, resulting in a better workout.

Am I missing something?

— Rory Rohde, Hamilton

In traffic discussions, our goal is conservation of matter. We want to keep travelers intact. Traffic safety is the applied science of avoiding collisions. Matter-to-energy calculations are safest when they involve supercolliders and neutrinos rather than roads and cyclists.

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