Dear Dr. Gridlock:

I was driving south on I-95 in Maryland the other day when I saw several Maryland State Police cars parked in the median between Baltimore and Washington. All of a sudden, a trooper jumped into the left lane and waved at an oncoming car to pull over.

The driver being summoned immediately pulled to his right to avoid hitting the trooper. Luckily, I saw him and quickly moved to my right. The car coming up on my right slammed on his brakes.

The result of this trooper's actions was cars swerving all over the place. Amazingly, no accidents occurred.

I understand the trooper was trying to pull over a speeder. However, I question his tactics. I doubt one of the requirements for being a Maryland state trooper is suicidal tendencies. Jumping out into the left lane of an interstate is an excellent way to get killed or create a major accident.

What is Maryland's policy on this? Is its procedure to stop speeders really to jump out in front of them? One can imagine the tragedy if the speeding driver wasn't paying attention.

RONALD BENDER

Arlington

The state police call this "stationary enforcement," and they periodically use the tactic on Interstate 95 between the Washington and Baltimore beltways.

It's up to the troopers to decide when this is safe, according to Sgt. Laura Lu Herman, a Maryland State Police spokeswoman. She said she is not aware of any accidents resulting from the tactic.

I agree with you, Mr. Bender. This sounds dangerous to the troopers and to motorists.

The speed limit on that section of I-95 is 65 mph, so speeders probably are exceeding 70 mph. Pedestrians are killed all the time trying to cross an interstate highway and failing to gauge such high-speed traffic. I don't think a uniform provides immunity from such a misjudgment.

I hope we won't be writing the obituary of one of these troopers -- or one of the drivers swerving to miss them. But if we do, it won't be a surprise.

Perverse Reversible Lanes

Dear Dr. Gridlock:

For the past month or so, the traffic lights on Canal Road NW between Arizona Avenue and Chain Bridge have been erratic. They do not indicate the appropriate reversing of lanes for rush hours. Some cars follow the erratic signing, while others use the lanes as they presumably should be used, with lane direction changing according to the hour of the day.

We have seen a number of near accidents. A serious accident (such as a head-on collision) is waiting to happen.

MARIAN BLUM

Chevy Chase

William McGuirk, Washington's traffic signals manager, said a faulty controller has been causing the problem. It should be fixed by the time you read this.

For any other traffic light concerns in the District, please feel free to contact McGuirk at 202-939-8087.

Signals Out of Sync

Dear Dr. Gridlock:

Help! The traffic lights coming into Rosslyn on Lee Highway (Route 29) are no longer in synchronization. The timing of three lights leading up to the Key Bridge and the Roosevelt Bridge has been changed. Why? What does Arlington County think they are doing?

GRANT A. BAKER

Arlington

Here is the response from Bob Garbacz, a traffic engineer with the Arlington Department of Public Works:

"The difficulties your readers experienced in Rosslyn resulted from the changeover to Arlington's new computerized traffic system. Every signal in Rosslyn had to be taken off-line for several days while being changed over. When off-line, the traffic signals lose all coordination.

"All should be corrected by now."

If you have any questions about traffic signals in Arlington, give Garbacz a call at 703-228-3576.

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

Dr. Gridlock appears Monday in the Metro section and Thursday in Loudoun Extra. 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.