As the century draws to a close, the following letter is offered as a symbol of 20th-century congestion in our area, and also as hope for the next century.

Dear Dr. Gridlock:

A few months back, I was driving up East Capitol Street and a Metro bus wanted to merge into traffic. I really didn't want to be behind that bus, so I was not going to let it get in front of me.

Then the bus driver's window opened and a hand emerged, holding a sign that said, "Please Let Me In."

I was so flabbergasted and impressed that I did let the bus in. Then the hand flipped the sign over to reveal the next phrase: "Thank You."

Wow, a please and a thank you in Washington traffic!

Because I had been stuck in traffic, I wasn't in a very good mood that day, but after that incident, I had a wonderful ride home. Common courtesy really can go a long way!

Roger Parker

Upper Marlboro

Thank you for a heartwarming holiday story. Perhaps in the next century, automobile manufacturers will include flip-out signs that say, "Please Let Me In" and "Thank you." Here's more on merging:

Dear Dr. Gridlock:

In your Dec. 9 column, you asked, "Why won't so many of our drivers let another person in?" Here's my take:

Countless times I've come across a sign like "Left Lane Closed 1/2 Mile Ahead." Most drivers begin merging to the right immediately, but here comes Mr. My-Time-Is-More-Valuable-Than-Your-Time, racing to the front of the line, past all those saps who have merged farther back.

Only at the front of the line does he put on his turn signal (maybe) and try to nose in. If I'm at the front of the line I can guarantee that such a driver is going to wait for at least one more car--mine--before he can merge. I hope others feel the same way.

Maybe if he were kept from bullying his way into the front of the line he'd merge back at the lane closing sign, like everyone else.

Ken Robert

Silver Spring

Dear Dr. Gridlock:

As for why drivers don't let people in, I have a pretty good idea: It's because the drivers behind you get ticked off and pressure you not to do it. They can't believe that you're actually letting someone in front of you. They're thinking, if the car in front of me lets that guy in, then there's AN ADDITIONAL CAR in front of me and that's going to slow me down!

So I better tailgate the person in front of me, so she doesn't let that guy in (and neither will I).

Jennifer Bramson

Centreville

Dear Dr. Gridlock:

My pet peeve is when I let someone in and they won't give a thank-you wave. Just a simple gesture would be appreciated.

Kenny Adams

Falls Church

I'm reminded of a "Seinfeld" show where Jerry let someone in and didn't get a wave. "Where's my thank-you wave?" he demanded indignantly. Maybe if more people waved, more people would be let in.

Dear Dr. Gridlock:

I don't take turns at merges because the signs don't say so. If Virginia wants us to alternate merge, they should put up signs.

Marilee J. Layman

Manassas

Dear Dr. Gridlock:

A reason for not letting people in is when they are behind you and get out of line in order to zoom around you and then cut in in front of you.

Christopher N. Schwartz

Silver Spring

Dear Dr. Gridlock:

In contrast to driver habits here, I can signal a lane change in Denver and drivers practically stop dead to let me in.

Lynne Milyko

Alexandria

Dear Dr. Gridlock:

I was in Toronto recently and had to drive during rush hour. It amazed me to see so many people behaving with such consideration for each other. People used turn signals, allowed each other to change lanes and to merge as needed. Although the traffic was very heavy, it still flowed smoothly because of those small things. And very little tailgating! I felt I was at Disney World!

Cherie Sandifer

Falls Church

I wonder why the driving cultures in Denver and Toronto are so different. Could it be that their transportation system is superior?

New Year's Resolutions

Dr. Gridlock is still welcoming your New Year's resolutions for local transportation officials and for each other. They should be short and to the point, such as, "Let's all resolve to allow another driver to merge in front of us at least once a day." Then maybe someone will let us in.

Longest Red Lights

Dr. Gridlock is still looking for the longest red lights in our area. I need your measurement, in seconds. No need to be concerned with pedestrian signals or arrows. Just the length of the red light facing you. Please include the direction you are traveling, the name of the cross street where the red light exists and the length of the light.

Another Riddle Resolved

Here is the answer to the license plate riddle: What kind of car was observed with the license plate HARK?

The answer, from Mike Hughes in Alexandria, is a 1960s vintage Triumph Herald, as in "Hark, the Herald Angels Sing."

Dr. Gridlock's assistant, Jessica Medinger, contributed to this column.

Dr. Gridlock appears Monday in the Metro section and Wednesday or Thursday in the Weekly and Extra sections. You can write to Dr. Gridlock, P.O. Box 3467, Fairfax, Va. 22038-3467, or e-mail him at drgridlock@washpost.com. The doctor's fax number is 703-352-3908. Please include your full name, address and day and evening phone numbers.