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:

The reasons these folks gave for refusing to allow "larger vehicles" to merge in front of them were, to say the least, disingenuous and self-serving.

By their logic, anything bigger than a compact is "dangerous." That includes work vans, trailers, etc. These workers don't "choose" these vehicles; their work requires that they do so.

How nice of these folks to single them out for a special kind of rudeness. Larger vehicles aren't any more dangerous than regular-size cars.

Beau James

Washington

Dear Dr. Gridlock:

As a faithful reader of your column and an SUV owner, I read the column about SUV owners having trouble merging with surprise, since this has never happened to me.

But immediately after purchasing my SUV, I became aware of one distinct benefit. My neighborhood has a number of intersections controlled only by four-way stop signs, which experience heavy volume during the rush hours, with the expected backups and impatient drivers.

When driving my SUV through these intersections, as opposed to my regular vehicle, hardly anyone ever tries to run a stop sign when it's my turn to cross the intersection. So the apparently intimidating effect of SUV driving can have some positive effects on traffic as well as negative.

Art Goldberg

Chevy Chase

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 drive an SUV because I am 6 feet 4 inches and 290 pounds. I have trouble fitting comfortably in a smaller vehicle. You're telling me that since I am a large man and I drive a large vehicle, I am to be treated differently on the road? Doesn't make much sense, does it?

Brad Griffith

Frederick

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:

Say what you like about our trucks. Moan and complain all you want. Complain about 18-wheelers, box trucks and the like. Food does not magically appear on your grocers shelf; houses just don't grow out of the ground; your clothes do not suddenly appear in stores; the gas you have in your car did not magically appear.

Not everyone who drives an SUV is an egomaniac; some are doctors, firefighters, policemen, hospital workers and the like, and they have to be able to get to work no matter what.

And besides, if you did not tailgate me, you might be able to see around me.

G.W. Green

South Riding

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

Transportation researcher Diane Mattingly contributed to this column.

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