Dear Dr. Gridlock:

Maybe some of your readers can answer this for me. The taxpayers paid for a very nice bicycle path through Rock Creek Park. And yet, whenever I drive through the park, many of bikers are riding on the road, not the path, even when the path is only about two feet away!

This is especially true in the Kensington area of the park. Can anyone tell me why the bikers would rather drive dangerously near passing cars, often holding up traffic, instead of on the terrific path built for their convenience?

Chris Core

Chevy Chase

I'll bet some readers can.

Not Quite an Emergency

Dear Dr. Gridlock:

In a recent column you recommended calling 911 to report a car illegally blocking traffic in Chevy Chase.

While blocking traffic is annoying, aggravating and troublesome for other drivers, it's not an emergency.

Calling 911 should be reserved for life-threatening situations, reporting crimes in progress and other emergencies.

Montgomery County has a nonemergency number for this kind of problem: 301-279-8000. In the District the nonemergency number for the police is 311.

Bill Adler

Washington

I think you're logical in making these assumptions. However, Dr. Gridlock was very careful to go over this with Officer Derek Baliles, a spokesman for the Montgomery County police. He recommended calling 911 to report vehicles parked in a lane of traffic on the reasoning that this was a traffic violation in progress. If an officer was available and nearby, he would be dispatched to the scene, Baliles said.

Double-Thinking an Idea

Dear Dr. Gridlock:

It seems clear that we will never solve our traffic problem with new roads because of the political difficulty of gaining approval for new routes.

The solution to our overburdened traffic system is to increase capacity without building new roads. Why not simply double-deck the existing roads?

Doubling the capacity of the Beltway and I-95 will do an enormous amount to solve our traffic problems.

The engineering problems will be difficult but solvable. I envision building the upper-deck sections in modules and positioning them with helicopters. That may not prove feasible, but our society is good at solving difficult construction problems.

This will cost an enormous amount of money and will save an enormous amount of time, money and hassle.

Stuart Plattner

Bethesda

Every now and then I get a letter suggesting the Beltway be double-decked. One of the problems is that building an elevated interstate highway (in effect, on a bridge) is infinitely more costly and more expensive to maintain than building a new road on a flat right of way.

Look at the Woodrow Wilson Bridge: $2.5 billion to build a new bridge and interchanges on each side. That is a fraction of the length of the Beltway.

I don't think the money is there for double-decked undertakings.

Go-and-Stop Method?

Dear Dr. Gridlock:

I wonder if you have any opinion on the British way of handling traffic lights. It's been a while since I have been there, but at the time their lights went from red to yellow to green. From green, they went directly to red.

This avoided having people mashing down on the gas when the yellow light warned of the light turning red, as people do here. Green to red means stop -- now.

Yellow means that cars waiting at a red light could proceed with caution, after checking for any cars not able to stop for the instant red light.

Robert Boise

Temple Hills

And we think we've got a problem with red light running now! Wow. You mean you're tooling along a secondary road at 45 mph, and as you approach a green light it suddenly and without warning changes to red? Can we say "Screech!" and "Ka-boom!" and rear-end collisions?

I don't see how this could work here, but as always, I will consider the wisdom of the readership. I'd like to hear your views.

A Tailgating Target

Dear Dr. Gridlock:

Is there a profile for people who tailgate? It happens to me quite often. I drive a small, four-cylinder car. When the air conditioning is on, my car will not accelerate quickly.

Do I forfeit my right to drive on I-95 because of this?

I do the speed limit, but a tailgater will attempt to push me faster in the right lane.

Laurel Jade

Columbia

The fact of driving life in our area is that no matter what lane you're in, or how fast you're going, some nut will try to run over your car. If you're staying right, and still getting tailgated, I don't know what to tell you. Maybe readers have a suggestion.

An Unneeded Diversion

Dear Dr. Gridlock:

I thought your answer to Mike Mills on [Sept. 29] was inappropriate. We have enough distractions to be listening to Books on Tape while we drive. Driving here demands our full attention. Who can concentrate on a book?

Sharon Anderson

Nokesville

Many readers have highly recommended audio books as a way to combat commuter tedium. I haven't heard them express your concern.

Transportation researcher Diane Mattingly contributed to this column.

Dr. Gridlock appears Sunday in the Metro section and Thursday in Montgomery Extra. You can write to Dr. Gridlock, 1150 15th St. NW, Washington, D.C. 20071. He prefers to receive e-mail, at drgridlock@washpost.com, or faxes, at 703-352-3908. Please include your full name, town, county and day and evening phone numbers. Dr. Gridlock cannot take phone calls.