Dear Dr. Gridlock:

Recently I was driving south on Interstate 95 and about to enter the Fort McHenry Tunnel. The far-right tollbooth's green light was on, but I found the booth door closed and no attendant.

I wasn't going to back up, so I went through and heard the buzzer. What should I have done?

Bob Koenig

Bethesda

You did the right thing. Officials don't want drivers backing up in traffic, because other motorists wouldn't be expecting it.

The buzzer indicated you had not paid the $2 toll. A photograph of your license plate was taken, and you will receive a bill for the toll. It is important to pay that promptly, according to Bryon Johnston, a spokesman for the Maryland Transportation Authority.

Johnston said it is unusual to find a booth unstaffed except in a dedicated lane for E-ZPass. He wonders if you got into an E-ZPass lane.

Slow Down to Save

Dear Dr. Gridlock:

With gas prices making operating my 2002 Toyota Sequoia more expensive, I have adopted a strategy of driving 5 to 10 mph lower than the posted speed limit to improve gas mileage.

As a result, I have noticed that navigating has been much smoother, and I feel safer.

However, I frequently notice that vehicles drive up close behind me and then speed around to pass on the left, as if I am impeding their travel.

I believe road mannerliness is an art that needs more attention and documentation in the region. I witness many signs of good and bad road manners.

I don't wish to inflame other drivers, which could create a more dangerous and expensive commute, nor do I want other drivers' impatience to cost me more money in fuel consumption. What should I do?

Drew Asher

Columbia

It depends on whether you are on an interstate highway or secondary roads. I would not recommend that you drive 45 mph on the Capital Beltway, which has a 55 mph speed limit, because people actually drive 70 to 80 mph there. I have the same advice for Interstate 95 between the Capital and Baltimore beltways.

You should be able to drive more slowly on secondary roads, as long as you can put up with the tailgaters who want to pass you.

I'd map out roads that are the least traveled and proceed with your method.

Railroad Crossing Rx

Dear Dr. Gridlock:

A few years back, I remember reading in one of your columns an address where one could report railroad crossings in need of repair. What is that address?

The railroad crossing on Route 6 in the town of La Plata is absolutely atrocious and in need of immediate attention, with many pieces of metal lying about and holes to suck up tires.

Whom can we complain to?

Andy Andrews

La Plata

CSX Corp. headquarters is in Jacksonville, Fla. Call 800-325-8182 with complaints. Please clip this out and put in the pocket of your vehicle. You may need it again.

Trains Too Short

Dear Dr. Gridlock:

I use the Blue Line to get to and from work and am astounded that at the height of rush hour, either 8 to 9 a.m. or after 5 p.m., Metro runs four-car trains.

Besides overloaded trains, this causes waiting passengers who spread out on the platform to run after the train and tackle other passengers who are positioned in front of the train doors.

What criteria does Metro use to determine how many cars run on a particular line? Also, who in their right mind would run four-car trains during rush hour?

Kristin St. John

Arlington

"We don't have any more cars," said Lisa Farbstein, Metro spokeswoman. "Right now, the Blue Line is the least crowded, so four- and six-car trains are all they need right now.

"More cars are due to arrive later this year, and on into 2006, and we will decide where they go. Our first priority is to make all four-car trains into six-car trains, and some of those into eight-car trains."

So, by that standard, you should see those four-car trains turned into six-car ones by the end of the year. Good news, I think.

Transportation researcher Diane Mattingly contributed to this column.

You can write to Dr. Gridlock at 1150 15th St. NW, Washington, D.C. 20071. He prefers e-mails, at drgridlock@washpost.com, or faxes, at 703-352-3908. Include your full name, town, county and day and evening telephone numbers. Dr. Gridlock cannot take phone calls.