Dear Dr. Gridlock:

Do you know if there are plans to address the long-term parking problems at Baltimore-Washington International Airport? The last four times I have been there for both personal and business travel (on weekdays or weekends), no long-term parking was available. I have never had this problem at Dulles.

On my most recent trip last month, I ended up paying $60 for three days' parking in the airport garage (it was raining, I had to catch my flight and the other alternative was $18 a day at the airport's "express" lot). I find this exorbitant.

Also, I find that the shuttle buses do not run as often at BWI as they do at Dulles.

Although I live equidistant from all three metropolitan airports and shop around for the best fares, I am currently avoiding BWI because of this situation.

Terrell Vanderah

Gaithersburg

This is a good opportunity to look at parking availability and cost, and shuttle connections at BWI, Dulles and National airports. Dr. Gridlock's assistant, Jessica Medinger, and Metro graphics editor Brenna Maloney have put together a nice display accompanying this column.

First, parking availability seems to be about the same at all three airports, although the satellite lots ($7 a day) at BWI are filling up more this summer, according to Marilyn Corbett, spokeswoman for the Maryland Aviation Administration. She said the airport is examining ways to develop more parking. The satellite lots are usually available at Dulles and National.

It's hard to see where the impression of more expensive parking at BWI comes from. Consider: The satellite lots are $7 a day at BWI, $8 a day at National and $6 a day at Dulles. Hourly lots are $18-20 a day at BWI, $28 at National and $27 at Dulles.

BWI doesn't have the equivalent of the daily lots found at National ($12) and Dulles ($10). You either park close to the terminal at BWI, at $18-20 a day in the Express Service Parking lot, or you park in one of two satellite lots.

According to the figures given to Medinger by Corbett and Tara Hamilton, of the Metropolitan Washington Airports Authority, parking shuttles run every 10 minutes at BWI, every 20 minutes at National, and every 10-15 minutes at Dulles.

At BWI during the major holiday seasons, Corbett said, two additional--and more distant--satellite lots are opened, also for $7 a day.

Corbett says that because of the increasing passenger traffic at BWI, the regular satellite lots have been filling up, as was the case apparently when Mr. Vanderah was traveling.

When satellite lots are full, messages are placed on AM 1040 and on the message boards near the airport, encouraging travelers to park at the nearby BWI Rail Station. It costs $5 to park there for a 24-hour period, and a free shuttle bus is scheduled every 15-20 minutes from 5 a.m. to 1 a.m. Motorists may park there any time.

If all satellite lots and the BWI Rail Station are full, then the terminal garage and the express lot rates are discounted, to a maximum of $9 for 24 hours.

Corbett also noted that travelers can avoid the parking issue by taking the MARC train on weekdays from Union Station to the BWI Rail Station, which costs $5 for a one-way ticket with a free shuttle to the BWI terminal. On the weekends, the cost on the Amtrak line is $17 one-way.

For more information on the parking options at BWI and to get an update of which lots are open, call 1-800-GO-TO-BWI. You can also get parking information at www.bwiairport.com, the airport's Web site.

Dr. Gridlock would like to hear your thoughts about transportation to, from and at our three major airports.

License Plate Riddle

The last license plate riddle was this: What kind of vehicle sports the plate that reads: PENNY LN?

A few souls suggested a Lincoln on the theory that that's the face on a penny. Nice try.

But the answer is found in a Beatles song:

Penny Lane is in my ears

and in my eyes

There beneath the Blue

suburban skies. . . .

The owner of "Penny Ln" was driving a blue Chevrolet Suburban.

Thank you for the lyrics and correct answer, Melvyn D. Gerald, of Washington. And thanks to all who made similar suggestions.

Now, Dr. Gridlock is seeking more license plate puzzles. Here's my next offering:

What kind of vehicle has a license plate that reads: IXXI?

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

Dr. Gridlock appears Monday in the Metro section and on 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.

Regional Airport Parking Fees

Maximum charges for a 24-hour period:

Baltimore Washington International Airport

Airport Terminal lot: $20 maximum.

Express Service Parking (ESP) lot: $18 maximum; shuttle bus runs on demand as needed.

Satellite lots: $7 maximum, 7th day is free; shuttle bus runs every 10 minutes.

Reagan National Airport

Hourly lot: $28 maximum.

Garage A and Daily B/C: $12 maxiumum.

Remote lot: $8 maximum; shuttle runs every 20 minutes.

Dulles International Airport

Hourly/short term: $27 maximum.

Daily: $10 maximum.

Satellite/long term: $6 maximum; shuttle every 10-15 minutes.

Valet: $25 first day, $12 each day following.