Dear Dr. Gridlock:

With the advent of the new 65 mph speed limit, I'm hoping to get my Trans Am above 1600 rpm. Where are the closest places to go to do this? Thanks. JON MUNROE Rockville

You might try West Virginia or North Carolina. But pay attention to posted signs, because this gets tricky.

Although most states now have 65 mph speed limits, that generally applies only on interstate highways and then only in rural areas.

For instance a Washingtonian recently traveling in California noticed a 65 mph speed limit on an interstate and assumed that speed limit existed on all major highways in that state. The California Highway Patrol explained the fine points of the law while issuing a ticket to that driver on U.S. 101 near Santa Barbara. Even though 101 is the major coastal highway in that state, and is six lanes and divided at that point, it is not an interstate, and even if it were, the speed limit still would have been 55 mph because that stretch was not in a rural area.

A federal law enacted in March allows states to decide whether to raise the speed limit to 65 mph on interstates in rural areas. So far, 36 states have raised the limit (see map), with Oregon joining the list on Sept. 26.

Maryland and Virginia did not jump on the bandwagon because enactment of the federal law was too late in their legislative sessions this year to receive proper consideration, according to authorities.

There is broad support for the measure among legislative leaders in Virginia, and the matter is expected to be introduced in Richmond at the General Assembly session in January. Some of the Virginia roads that could be considered for the higher speed limit include I-95 between the Prince William County line and the Richmond-Petersburg Turnpike; I-95 between Petersburg and the North Carolina line; most of I-81; I-66 west of Fairfax, and possibly some segments of I-64 between Richmond and Norfolk.

There appears to be a different sentiment in Maryland. State Highway Administrator Hal Kassoff said that even though his office is studying the matter, he is "very skeptical about the wisdom" of raising the speed limit. Kassoff points out that Maryland is a "compact, mostly urban" state with few long stretches of interstate through rural areas. Among those segments that might qualify would be I-81 in Washington County to the Pennsylvania line, I-70 between the Baltimore Beltway and Frederick, and possibly the northern tip of I-83 near the Pennsylvania state line. The segment of I-95 between Baltimore and Washington would not qualify, he said.

Kassoff said having interstates with both 55 and 65 mph speed limits in such an urban state might cause confusion and speed differentials between the 55 mph and 65 mph set that could cause more accidents. Kassoff said he is not aware of any group lobbying to raise the speed limit in Maryland.

At a news conference Aug. 14, Maryland Gov. William Donald Schaefer said: "I don't favor it . . . . When you go 55, they go by you like you are standing still. So if you go up to 65, they'll go by you like you're standing still. I am not happy about raising that speed limit." Poorly Marked Signs on 14th St. Bridge Dear Dr. Gridlock:

Last week, as I drove my husband and children northbound on Shirley Highway {I-395} during morning rush hour, I came upon a D.C. roadblock on the HOV lanes of the 14th Street bridge. I assumed they were stopping violators of the HOV restrictions. But I got a very unpleasant surprise when the policeman pulled me over and presented me with a $50 ticket for speeding in the HOV lanes.

I was told that the 55 mph speed limit in Virginia drops to 40 mph when I crossed into D.C. on the bridge, but I couldn't recall seeing a sign. So I checked the next day for speed limit signs on the HOV northbound lanes and found only one very poorly marked speed limit -- half covered by another sign above it which had fallen over on top of it -- totally blocking the words "speed limit" and part of the number "40."

I'm a new resident of Virginia (having moved from the District), and this is the first ticket I've gotten in nearly 20 years. I think the D.C. police are taking advantage of commuters who don't realize they are breaking the laws because the roads are poorly marked. And they can't use the excuse that nearly all speed limits in the District are 40 mph or below -- I saw no sign on the HOV lane that tells you where the District boundary begins. I'm thinking about fighting it in court, but I can't figure out how to get a picture of that speed limit sign without risking my life and limb -- and another ticket -- by stopping on the bridge.

Why not clearly mark the speed limit, then spend that same police power catching commuters who drive on the shoulder during rush hour, or for more roadblocks to apprehend drunk drivers at night? And it certainly doesn't encourage use of the HOV lane, if car poolers know that D.C. cops are lurking on the car pool lanes nearly every day. BARBARA C. GLEASON Alexandria

The D.C. Department of Public Works, advised of your letter, promises to put up more signs.

Dr. Gridlock appears in this section each Friday to explore what makes it difficult to get around on roads, from misleading signs to parking problems to chronic bottlenecks. We'll try to find out why bad situations exist and what is being done about them. You can suggest problems by writing to GRIDLOCK, c/o The Washington Post, 1150 15th St. NW, Washington, D.C. 20071. Please include your full name, address and day and evening phone numbers.