Dear Dr. Gridlock:

In response to a recent column about smoking on the Metro escalators, I was under the impression that smoking was banned throughout the entire Metro system.

Secondhand smoke, whether in the air or clinging to your clothes, can set off an asthma attack. I was on a commuter bus recently when a passenger who had just put out her cigarette got on and sat beside an asthmatic passenger.

The man started gasping, choking and struggling for air. He had to be let off the bus and called his wife to pick him up. He couldn't make it to work that day, all because of secondhand smoke clinging to someone else's clothes. I haven't seen him on the bus since then, and I hope he's okay.

Smoking stinks. Asthma is frightening. Smokers should be aware that a serious asthma attack can result in death.

Bev Barth

Prince Frederick

Smoking is illegal only on some Metro escalators, depending on whether they are open, covered or enclosed and on the laws of the various jurisdictions.

Views on Taller Vehicles In the Sept. 29 column, reader Ruth Mundell said that since she traded an old station wagon for a Jeep Wrangler, she was having trouble being allowed to merge. It seems that more people wouldn't let her in. She asked why. Some explained themselves in the Oct. 17 column. Here is another round of driver thinking about who should get to merge in front of whom:

Dear Dr. Gridlock:

I drive an SUV, and it drives me crazy when people won't let me in.

I always make it a point to put on my turn signal when I'm going to change lanes. But it seems when you do that, people will speed up so you can't merge.

All these people who do that show no courtesy whatsoever and need to go back to driving school.

I can't help it if my car is taller than your car. In the end, the actions of other drivers have forced me to be more aggressive.

When I put my turn signal on and see one of these people who won't let me merge or will speed up, I will just switch lanes faster.

If everyone would just be a little more considerate of others instead of being so egocentric, driving would be a much easier experience.

Jason Frantz

Silver Spring

Dear Dr. Gridlock:

I consider people who own and drive SUVs to be unconcerned over the safety of my family, ignorant of the potential dangers to their own families, cavalier about the environment, and unable to maneuver their dragons through traffic safely and efficiently.

I also think some of them are socially clueless to assume others are jealous of their owning or leasing such environmental disasters.

Legislators should require that headlights on SUVs be lowered, so that those responsible individuals among us are no longer blinded by the towering SUV behind us. I support the implementation of "No SUVs" lanes on interstates and major highways, similar to the "No Trucks" lanes.

Jody Chase

Rockville

Dear Dr. Gridlock:

I really don't think it is the height, style or cost of the vehicle. . . . People are inherently rude or, a least, just not nice. They may be perfectly kind people when walking down the street; if you say "excuse me" they will be more than happy to let you walk by.

In their cars, their true demeanor comes out. I actually make a conscious attempt to be just as nice or nicer in my car as I am walking down the street. This is from a former "road warrior," and I find I have a much more pleasant and less stressful drive.

Butch Zachrel

Poolesville

Dear Dr. Gridlock:

Concerning the large vehicles merging into traffic, most of your respondents seem to include large vans in this category. Let me enlighten your readers.

Many noncommercial full-size vans are used by people with disabilities, myself included. I am paralyzed and use hand controls and an automatic lift, which is best used in a full-size van.

So please, dear readers, keep that in mind next time you see a full-size van with a conversion top trying to merge. It was not my choice to purchase this behemoth vehicle; it was a necessity.

Rebecca Mattingly

Bowie

Dear Dr. Gridlock:

I read your column today about drivers being discourteous and refusing to let the woman with the Jeep Wrangler merge into traffic (among other vehicles) and the various excuses (yes, they are excuses) for that.

I call them excuses because I drive a 2002 Mitsubishi Lancer, and the same thing happens to me. The Lancer is an extremely inexpensive four-door sedan. No one has a problem seeing the road ahead with me in front of them, and I still have problems trying to merge into traffic. The real problem is that everyone on the road has the "me first" attitude.

The thing that really irritates me is when I'm trying to get over to the right, some idiot will undoubtedly try to pass me on the right and not let me over. Here's a hint: If you see a car that was going a bit faster in the left lanes slowing down and trying to change lanes to the right, it's a good bet that the person's exit is coming up and they're trying to leave the highway. Let them over!

J.D. Walker

Alexandria

Dear Dr. Gridlock:

I drive an 18-year-old Ford Ranger pickup and do allow others to merge in front of me, regardless of size; it's part of the courteous driving habits I learned 30-plus years ago during my behind-the-wheel driver's training in high school in California. Heck, I even allow line-jumpers (those drivers who use the merge lane to get in front of others) to merge!

One also wonders just how much our "winning is all that matters" culture affects our driving habits; some people may not allow others to merge just because the merging driver would then be ahead of them, thus "winning."

One thing I've noticed: Not everybody signals lane changes, and some of those who do only do so after they've started to change lanes. I still follow the habit I learned 30-plus years ago: Signal for at least 100 feet before changing lanes or turning. Of course even after doing so, I've still had people honk at me when I do change lanes.

Edward Lloyd Hillman

Centreville

Transportation researcher Diane Mattingly contributed to this column.

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.