Dear Dr. Gridlock:

Concerning your advice to give a simple, short toot for those not turning right on red where permitted [Dr. Gridlock, May 6]: I remember reading in your column a long time ago that right turn on red is permissible and not mandatory. In other words, one does not have to turn right on red but can wait for a green light or arrow.

As a result, whenever I am behind cars that are not turning right on red, I do not honk, even briefly, figuring that the driver might be uncomfortable making the turn.

What do law enforcement authorities advise for drivers behind cars that do not turn right on red where traffic permits such a turn?

Rany Simms

Fairfax Station

It's not a question of law, because there is no law that requires a vehicle to turn right on red.

One law enforcement source I talked with said he usually gives a slight toot in case the motorist is daydreaming. That's what I do, too.

Dear Dr. Gridlock:

The law that permits a right turn on red does not require it. Only the driver at the intersection is in a position to determine whether the action is safe. Honking at the lead vehicle usually does not help, because the most natural response is to look behind, not forward.

Barbara Peters

Annandale

Truck-Congested I-81

Dear Dr. Gridlock:

Just a comment on traveling on Interstate 81 as an alternative to the Interstate 95 corridor. If you don't mind sharing the road with lots of 18-wheel trucks, then drive I-81. It is a four-lane divided highway north and south from where I get on it, at Interstate 66, to where it turns into Interstate 40.

For every 10 cars there are six trucks, which is not great, especially if the weather is not good. Rain is horrible, with the big trucks splashing their spray on you.

Ed White

Annandale

You are so right. I-81 is one of the most popular truck corridors in the country.

The Virginia Department of Transportation is negotiating with a private company, Star Solutions, to make improvements to the corridor that might include new, trucks-only lanes.

The shape, cost and funding of any new improvements, plus environmental studies, are matters of discussion at least until the end of this year.

Mid-Block Light a Pain

Dear Dr. Gridlock:

The mid-block traffic light on 18th Street between K and L streets NW is a royal pain at 5:30 a.m., when there is no traffic emerging from the private parking garage.

Bill Brykczynski

Fairfax

A private concern bought its own traffic light from the city and stationed it mid-block so garage customers can more easily enter 18th Street. The problem you highlight is one more reason the city should not sell traffic lights.

Above and Beyond

Dear Dr. Gridlock:

There are so many complaints about Metro personnel, but one particular Metro employee went above and beyond, and I hope there is some way to let Metro's management know about it.

On April 9 I got into an empty train car at the Vienna Metro station about 4:15 p.m. Shortly after that a family of four joined me.

They asked me if the train would take them to Dunn Loring. I told them it would and gestured to the map on the wall. They told me they were so lost they wouldn't understand the map, didn't know where they were and were completely overwhelmed. I continued to talk to them and learned they are from Staunton, Va., and were staying at a hotel in Tysons Corner. They'd entered the Metro system at Dunn Loring and had spent the day sightseeing on the Mall.

On their return, they'd missed getting off at the right station, and when they exited at Vienna and went up the escalator, they didn't recognize the stop at all.

They said they were approached by a Metro employee who said they looked like they needed help -- they didn't even have to ask! She told them to get back on the train and which stop they needed and then called their hotel to have the shuttle meet them at the stop so they wouldn't have to wait, which I thought was especially kind of her.

They got off at Dunn Loring, and I assume they made it back to their hotel uneventfully.

Thought you'd like some good news for a change.

Aubrey Hamilton

Vienna

Always. It is so good when public servants go out of their way to help distressed people.

A Suburban Problem?

Dear Dr. Gridlock:

Regarding the difficulty a Capitol Hill resident was having finding parking to unload groceries: The problem is with commuters from the suburbs.

Let's be realistic. First, you live outside the Beltway, and thus it continues to be very clear that you have a very large conflict of interest, as well as prejudice, regarding the problems of Capitol Hill residents and where we park.

Second, much of the parking problem on Capitol Hill can be attributed to the fact that commuters from outside the Beltway are given preference over residents. There are several Capitol Hill streets that should allow parking on both sides: Independence and Constitution avenues, the streets surrounding Stanton Park and Lincoln Park, and others.

Unfortunately, this city has such a low opinion of itself that we fail to extend even the basic courtesies to ourselves. Here are a few sample courtesies that this city seems to be lacking:

1. Commuter traffic should never be routed through residential streets.

2. New construction in established neighborhoods should be required to offer parking for the new residents or businesses that are being created.

The person unloading groceries is most likely a tax-paying resident. Why would the city fine that person for something that is perfectly logical? It was probably only the non-tax-paying commuters who were creating the traffic-clogging problem. Fine the commuters for clogging up residential streets in the first place.

Barbara M. Leach

Washington

Residential parking permits are designed to favor D.C. residents over commuters from the suburbs. Signs limit parking to two hours unless a zone sticker is displayed. Is this system not working?

Dangers of SUVs

Dear Dr. Gridlock:

I would like very much to start a dialogue in your column regarding the book "High and Mighty: SUVs -- The World's Most Dangerous Vehicles and How They Got That Way." The author documents reasons purchasers of SUVs are considered by the automotive industry to be egotistical, paranoid, gullible saps who are at the mercy of the millions of dollars spent on marketing.

The book presents crash data showing that SUVs are more hazardous to their occupants than are large automobiles, such as the Crown Victoria.

A huge percentage of the advertising revenue of The Washington Post Co. comes from the automotive industry and automotive dealers in this region.

Companies selling SUVs are killing people as surely as the tobacco industry, the asbestos industry and, very likely, the cell phone industry.

Dare we forget the legacy of the Pinto and the Corvair? Dare you take on this travesty?

Peter Whitehead

Alexandria

According to the book jacket, "High and Mighty" shows why SUVs:

* Are no safer for their occupants than cars.

* Have worse brakes than cars.

* Are especially poor choices for teenagers to drive.

* Have a rollover problem that goes far beyond the failures of Firestone tires on Ford Explorers.

The book is written by Keith Bradsher, formerly the New York Times bureau chief in Detroit.

My biggest complaint with SUVs is that their higher headlights strike other drivers at eye level and can cause temporary blindness. Also, from what I've seen on the rollover potential, I wouldn't want my teenager in one.

Your thoughts on SUVs?

No Excuse for Rudeness

Dear Dr. Gridlock:

I want to comment on the people who think they have the right to leave shopping carts where they want just because they have kids.

I have three small children, and here is what I try to do. First, I try to park next to a cart stall. Second, if I can't park next to the stall, I just load my groceries and then take the cart back with my kids in it and carry them back to the car.

It takes a few extra minutes, but it's better than leaving the kids in the car or just being rude and leaving the cart there.

Valerie Denizard

Leesburg

Bicycle Commuting

Dear Dr. Gridlock:

I commute by bicycle from Lee Highway near the Courthouse Metro stop to 20th and L streets NW. It takes less time than using Metro.

I take the Custis Trail (runs parallel to Interstate 66) across the Key Bridge. From the bridge, I enter tiny Francis Scott Key Park and walk my bike down the stairs and ramp to the street-side path along the C&O Canal. From there I ride until the trail ends and circle up to Pennsylvania Avenue near the Four Seasons Hotel in Georgetown. Then the dangerous, adrenaline-rush, life-threatening part of my commute begins.

What I usually do is make the slight left turn onto L Street, which is safer than trying to make it through the "Circle of Death" (Washington Circle).

Elissa David

Arlington

I commend you for an inexpensive commute that is also wonderful exercise.

Dear Dr. Gridlock:

In passing along help for bicyclists [Dr. Gridlock, March 25], you might have included a map or list of major bike routes, advice from cyclists and references to helpful groups such as the Washington Area Bicyclist Association and www.bikewashington.org.

Jack Cochrane

Bethesda

This column has never suffered from a lack of ideas from bicyclists. I'd like to hear your favorite resources.

Interstates Through Cities

Dear Dr. Gridlock:

I have been to most major cities in the country, and the one common feature is interstate highways through the middle of the cities. East to west and north to south. Washington and Baltimore are the only exceptions I am aware of.

I remember seeing the original layout of Interstate 95, and it went right through Washington, not around it. I say, put that highway back where it belongs. Also, connect Route 50 to Interstate 395 to help solve the east-to-west problem.

Gerry Ridgeway

Severna Park

I-95 was designed to go through the city, but city leaders decided they didn't want it. So the road money was transferred to the Metro system. Who is to say that was a bad trade?

Is it better to have cities compartmentalized into interstate grids, like Los Angeles, or simply cut in two, like Atlanta, where the state capital and the Martin Luther King monuments are only a few blocks away but are divided by an interstate highway?

There is little chance that I-95 will now be routed through the nation's capital.

Transportation researcher Diane Mattingly contributed to this column.

Dr. Gridlock appears Sunday in the Metro section and Thursday in 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.