Dear Dr. Gridlock:

This isn't an earthshaking issue, but if implemented it might reduce congestion. Currently, mail trucks (the large semis) leave the regional U.S. post office at Merrifield by turning right onto Prosperity Avenue, right onto Lee Highway (Route 29), right onto Gallows Road and then left onto Route 50 (and then to the Capital Beltway).

If they turned left onto Prosperity Avenue when leaving, they could then turn left onto Route 50, avoiding the busy intersection of Route 29 and Gallows Road.

Is there a reason they do not do so?

Bill Schenck

Falls Church

Mr. Schenck also sent his inquiry to Fairfax County Supervisor Gerald E. Connolly (D-Providence), who gives a thoughtful response:

"Currently, an eight-ton weight limit exists on Route 50 between the D.C./Arlington County line and Fairfax City, with the exception of the area immediately adjacent to the Beltway interchange. This weight restriction exists because the substructure under the pavement along Route 50 is several decades old and cannot support heavy trucks.

"At the request of myself and Del. Jim Scott (D-Fairfax), staff from [the Virginia Department of Transportation] has looked at the costs to rebuild Route 50 from Prosperity Avenue to the Beltway to accommodate trucks and alleviate congestion at the Route 29/Gallows Road intersection. The cost estimate for this project is approximately $3.2 million, which would be required to raise the pavement and rebuild the existing curb and gutter system.

"Because VDOT is scheduled to widen Route 29 and improve the Gallows Road/Route 29 intersection beginning in late 2004, money has not been allocated to improving Route 50."

Thank you for your response, sir. It looks like we are both in the business of trying to help people. In that vein, I have a few more questions:

* Any improvements at Route 29/Gallows Road seem a long way off. At the same time, $3 million is a pittance compared with other VDOT highway projects. Why not make the Route 50 substructure improvements now and bring more immediate relief to the overburdened Route 29/Gallows Road intersection?

* Dr. Gridlock has been trying for years to get this next problem fixed. Maybe you could have more success. The U.S. Postal Service regional headquarters in Merrifield is hard to find at night because it is set back far from Route 29, and there are many curb cuts that could be an entrance, but it is not clear which is the correct one. Some have "Do Not Enter" signs.

I suspect many motorists, like me, have thought they guessed right only to wind up in a Texaco station. Motorists who slow to figure this out are a safety hazard on Route 29.

A few roadside signs would fix this. From inbound Route 29, a sign that says "U.S. Post Office, Second Right" would be helpful, along with a U.S. post office sign at the roadside entrance, with clearly marked "entrance" signs.

This is the main post office facility in Northern Virginia, but for many looking for it, it's a secret.

Thank you for your help.

Dear Dr. Gridlock:

I am a lieutenant with the D.C. Fire and EMS Department who lives in Loudoun County. I cannot begin to tell you the number of times I have been involved with close calls on an accident scene.

When in doubt, I will not hesitate to close a road to ensure the safety of the patient as well as the emergency personnel on scene.

About a month ago, I responded to an accident on the outbound lane of the Roosevelt Bridge. The car was in the right lane and the patient was okay, so we only closed the right lane.

After we had completed our mission, we left the scene, turned around in Arlington and headed back into D.C. As we passed the original scene on the inbound lanes of the Roosevelt Bridge, I noticed another accident in the left lane of the outbound lanes.

One car had slowed down to see the initial accident, and the car behind him was also looking at the accident and did not see the car in front of him stop. Yes, he hit him. Turning around in the District, back to the scene we go. We tried to keep the middle lane open, giving each of the three outbound lanes a turn to get through.

As the ambulance worked its way through the residual congestion, a limo rode the tail of the ambulance, weaving in and out of lanes and following way too close. (D.C. police observed this and proceeded to cite this driver, whose time was obviously more important than anyone else's.)

At this point we had no choice but to shut down the bridge for about 15 minutes. I urge you, the good doctor, to go out and ride with the different area fire and rescue personnel and see firsthand what we are up against when it comes to the motoring public.

Kevin Stuart

Sterling

I feel your pain, Lt. Stuart. We rejoice at police ticketing that limo driver.

Drivers, please slow down and yield to rescue personnel and their vehicles, and to police at accident sites. The burden is on us to comply with the common-sense traffic conditions at an accident scene. That doesn't mean blocking the shoulder or racing behind rescue equipment.

What is frustrating to us ordinary motorists, however, is coming upon an accident scene and seeing a group of uniformed people standing around, talking to each other, with no one directing traffic. That seems more often the case than not.

If you can make a difference in a few such circumstances, Lt. Stuart, that will mean a lot more to relieving gridlock -- and promoting safety -- than my ride-along observations. Godspeed, sir.

Dr. Gridlock has had several letters complaining about running water and ice near Canal Road and Foxhall Road NW in Washington.

The problem is a break in a water pipe. City officials have been working to build a berm to direct water into a drain so that it won't collect on roads.

Because the leak is in the C&O National Historical Park, the permanent repair will begin after consultation with the National Park Service. There may be some lane closures, but standing, frozen water in this area should be alleviated now, according to city officials.

Keep me posted.

Dear Dr. Gridlock:

This morning I noticed, while waiting for a traffic light at Connecticut Avenue and N Street NW, that a "Walk" signal was leading pedestrians into the traffic flow of a left-turn arrow on Connecticut Avenue northbound. How dangerous!

Kadidia Thiero

Washington

Dan Tangherlini, director of the D.C. Division of Transportation, responded by e-mail: "Wow, that IS a problem. I have forwarded it to our signal folks so they can address it ASAP."

Dr. Gridlock's assistant, Lori Fischer, contributed to this column.

Dr. Gridlock appears Monday in the Metro section and Thursday in the Weeklies. You can write to Dr. Gridlock, P.O. Box 3467, Fairfax, Va. 22038-3467, or e-mail him at drgridlock@washpost.com. The Doctor's fax number is 703-352-3908. Please include your full name, town, county, and day and evening phone numbers. Because of the number of responses, Dr. Gridlock cannot take phone calls.