Dear Dr. Gridlock:

High-intensity-discharge headlights, or even misaligned headlights, pose significant threats to people on two wheels. Unlike cars, motorcycles do not have a rearview mirror that flips up or down. Also, our side mirrors are a lot closer together. That puts much more glare directly into our eyes and makes it significantly more difficult for us to avoid the lights.

Unfortunately, I sometimes feel the only solution is to adjust a side mirror, which not only eliminates the use of that mirror but also is dangerous to do while riding.

Please remind people to keep their headlights adjusted properly and add my name to the list of people against high-intensity-discharge headlights.

Daniel Hoult

Rockville

I'm on that list, too. Federal officials who gave a green light to these lights should be sentenced to look at them several seconds a day.

Stuck in the Middle

Dear Dr. Gridlock:

Recently, your column discussed turning left on a green light.

Although it is legal to move into an intersection pending completion of a left turn, what happens if one is still stuck in an intersection when the light changes to red, and the intersection is home to a red-light camera?

Hal M. Davison

Montgomery Village

At typical intersections, you are allowed to enter on green and complete your turn when it's safe or when oncoming vehicles have stopped.

For intersections with red-light cameras, it's my understanding that they are triggered when someone enters the intersection against a red light, which would exclude those who enter legally on green.

Costly Parking Woes

Dear Dr. Gridlock:

I started parking in the garage at my office building in Northwest Washington. I pay almost $200 a month, three times as much as the cost of commuting on Metro. But I have a new baby and think the ability to get to the caregiver at a moment's notice is worth the additional cost.

Having said that, the parking garage is the most stressful part of my day. Every space, ramp and aisle is so full you can barely drive. I spend 15 to 20 minutes most days waiting for the parking attendants to move cars so I can get mine out.

One day at lunchtime I went to retrieve something in my car. If there had been an emergency and I had to get to the babysitter's to get my daughter, the attendants would have had to move 15 cars (not in spaces) so I could have gotten mine out.

Mary K. Dillon

Arlington

My sympathies. Contact Commuter Connections, 800-745-RIDE or www.commuterconnections.org. Ask about the guaranteed ride home in emergencies.

If you take public transit or carpool to work, this program will pay for a ride home by taxi or some other method up to four times a year for a home emergency or unscheduled overtime.

You can take Metro, or they'll match you up with a car pool, which should be easy in Arlington. You can save more than $1,000 a year, wave goodbye to that stressful garage situation and contribute to cleaner air.

Let me know if this works out.

For more information, visit www.xmradio.com/index.jsp.

Parking Dibs

Dear Dr. Gridlock:

This has happened to me twice in the past month, the first time at Tysons Corner Center and the second time at the Tysons Galleria mall.

Parking is always hard to find at either mall, so rather than just drive around aimlessly, I waited in the lot for someone to leave. Each time, someone was returning to the car in the row I was waiting in, and both times, another driver came zooming in from another area of the lot to "claim" the spot.

I have always been under the impression that it was understood that the driver already waiting in that row has dibs on the spot about to open up. I guess no one else told those two.

The first time, the driver drove around me, cut me off and took the spot. The second time, the driver tried the same tactic, but my "dirty look" persuaded her to find another spot.

What's your opinion? Does the person waiting patiently in a row deserve the spot?

Steve Rothenberg

Lansdowne

Yes, but first it must be made clear that the vehicle is waiting for that spot. That can be done by waiting in the aisle, adjacent to the vehicle pulling out, with your turn signal on.

If others aren't sure of your intentions, we can't blame them for their me-first attitude. If they are, shame on them.

Anyone have any other ideas to thwart parking-space pilferers?

Taillights Needed for Visibility

Dear Dr. Gridlock:

It's not the lack of headlights that bothers me during rain, but rather the fact that when the headlights aren't lit, the taillights aren't, either. Taillights are most important during poor visibility.

With all the other safety features required on vehicles today, why not the simple one of automatically turning on headlights (and taillights) when the wipers turn on?

Emil Klingenfus

Manassas

No argument here.

Adding a Lane as Needed

Dear Dr. Gridlock:

I moved to the area in 1995. Since I have been here, there has been a large vehicle of some sort parked on the Theodore Roosevelt Bridge near the E Street exit.

What is that, and why has it been there so long? It does not seem to serve any purpose, except as a distraction.

Alexandra Simpson

Fairfax

Oh, but it does serve a purpose. The machine moves the Jersey barriers in the bridge median to allow for one more lane in the direction of rush-hour traffic.

In the morning, the bridge is four lanes eastbound and three lanes westbound. In the evening, it is four lanes westbound and three eastbound.

That is a huge benefit to Virginia commuters. The bridge is owned by the District. The Virginia Department of Transportation pays for the machine and the driver.

Parking Next to SUVs

Dear Dr. Gridlock:

In your April 8 column, John Horvath wrote that when backing out of a parking space from between two SUVs, "one can see oncoming traffic through tinted windows of vehicles parked next to you."

Because he drives an SUV, he can see through. In my Cavalier, the view is still obstructed, because my windows don't line up with those of an SUV. His other suggestions -- opening a window to listen for oncoming traffic and backing slowly -- are good ones and apply to all vehicles.

Steven Wadding

Beltsville

Dear Dr. Gridlock:

I think John Horvath missed the point about parking between two SUVs. The danger is for small cars that end up between these fortresses.

My little Saturn is low to the ground, and the fortresses seem a mile high. I, too, feel very uneasy. It's true that backing out very slowly is the way to do it, but even doing that, I'm praying the whole time because there are motorists who come barreling through with blindfolds on.

That was very gentlemanly of him to suggest that normal cars park way out. How about a corral for the beastly SUVs out in the pasture?

Margaret Sienko

Silver Spring

This is a problem for modern times. My suggestion would be to park as far away from the front door as possible, in a pull-through space, decreasing the chances of encountering an SUV next to you. They bug me, too.

Driving to Florida

Dear Dr. Gridlock:

Your April 11 column discussed alternatives to the Interstate 95 corridor to Florida. I routinely use the I-81 to I-77 route through the Shenandoah Valley, mentioned by a reader, although I usually stop in South Carolina.

I take I-77 to Columbia, S.C., and then head east on I-26 to catch I-95. Once on I-26, it's about one hour to the I-95 interchange. If you stay on I-26 east, it's another hour to Charleston, S.C.

There is one problem with I-81 that your reader didn't mention: It's a major truck route, so much so that I recently read a column about proposed separate lanes for trucks. Even with the trucks, I prefer that route over I-95. The scenery through the mountains is lovely.

An added advantage for me: When I get tired of driving and need a break, there are numerous antique malls along the way; I still haven't been to all of them.

Judy Carroll

Rockville

Thanks for the tips. Given the allure of antiques, I wonder about the cost of the alternate route.

I would still like someone to measure the I-81/I-77 route vs. staying on I-95.

And, yes, the Virginia Department of Transportation is looking at ways to build truck-only lanes on I-81. The trucks are a big problem.

Staying to the Right

Dear Dr. Gridlock:

Keeping slower cars to the right and using the left lanes only to pass is one of the most important and effective driving principles in safely and efficiently moving traffic along our crowded roads.

Although I will not go as far as to say that this area has an inordinate number of left-lane "squatters," I agree there is an unusually large number of left-lane exit ramps and left-lane on-ramp merges.

Some highway engineers have clearly ignored long-established practices to save a few bucks. The long-term consequences of such poor decisions will be increased congestion and more accidents as slow traffic moves left to exit and faster traffic passes to the right -- both major no-no's.

Andrew Chen

Clarksville

XM Radio

Dear Dr. Gridlock:

I was happy to see your suggestion of XM Satellite Radio for its 24-hour traffic updates [Dr. Gridlock, April 8]. I began subscribing to it six months ago and have never thought twice about the $9.95 monthly fee.

I carry the portable unit from my home stereo to my car to my office. I listen to it all day. I always find a station to suit my mood.

The addition of XM instant traffic and weather has been great. Once I know the status of my commute, I like to listen to the rush-hour information for other cities -- and, in most cases, be glad I'm not there!

Susan Zelenka

Arlington

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.