When it comes to automobile safety inspections, the three jurisdictions in our metropolitan area treat citizens very differently.

Consider this: In Maryland, a safety inspection takes 60 to 75 minutes. In Virginia, it takes 20 minutes. In the District, three to five.

The District and Virginia require safety inspections once a year. Maryland doesn't ask for one at all unless you're selling your car or transferring the title. Police in all three jurisdictions say they cite motorists with cars that appear obviously faulty, such as those with bald tires or mufflers banging on the street.

In Northern Virginia, you can get an inspection at any of 560 gasoline stations or auto service centers. In the District, the city government insists on doing all inspections but provides only two places to get them done, so sometimes lines are insufferably long. In Maryland, 1,500 gasoline stations or auto service centers do the work, including about 600 in Montgomery and Prince George's counties alone. And because the inspections take so long, motorists often make an appointment, or drop the car off for a day.

Maryland inspectors are supposed to take the car on a test drive and remove one tire front and rear to inspect brake linings.

Virginia inspectors are required to drive the car into the inspection stall and to remove at least one tire front and rear, although an informal survey of Virginia drivers indicates that many times neither is done.

District inspectors normally do not pull tires, relying instead on a machine that can test stopping efficiency.

About 40 percent of vehicles inspected in the District fail. The figure is 50 percent in Maryland, 35 percent in Virginia.

The wide variations in approach sometimes lead to awkward circumstances. A woman in Virginia had her car inspected to Virginia's satisfaction just before selling it to a Maryland woman. However, when the Maryland woman took the car in for that state's inspection, the car failed, forcing the seller to put hundreds of dollars into the car before she could complete the sale. A Virginia trooper said he has heard the reverse of that story. "Depends on the inspector," he said.

Officials in each jurisdiction say they have studied how others do this task, and think their method works just fine.

But some readers wonder. Dear Dr. Gridlock:

Maryland has the toughest inspections in the area, but cars are only inspected at a change of ownership. The burden of continuing enforcement falls on the police. Police officers cannot see many of the safety items that can fail. Additionally, police are often concerned with more pressing matters. The number of safety regulations fills a book too large to memorize. This is a ludicrous situation.

It is time for the state to realize that cars are being neglected. A significant number are on the road with worn brakes and faulty steering, and no system is in place to require owners to perform the necessary repairs.

The people of Maryland can only improve this situation by asking that their representatives reform these laws. It can take years of pressure to get the government to act, and now is the time to start. DORE SHARF Germantown

A couple of Montgomery County legislators are among those who have pressed for annual inspections, without success. State Sen. Ida G. Ruben (D-Montgomery) tried several times in the 1970s. She said her measure failed because of the $8 million it would cost the state to set up the needed stations.

"I think it wound up costing too much by the time we got into it," Ruben recalled. "I believe the District and Virginia put in their programs long ago." (Virginia was one of the first states in the country to have automobile inspections, starting in 1932. The District began its program in 1939.)

Del. Sheila Ellis Hixson (D-Montgomery) tried a different tack: to have service stations conduct annual inspections, as in Virginia. She lost out amid concerns about the difficulty in monitoring the stations.

"Opponents kept pointing out that it would be ripe for abuse, because the customers would know people at the neighborhood gas station," she said. "Some used-car dealers were opposed to the legislation too. I asked them for documentation of any of these concerns, and they didn't have any."

Ironically, the safety inspection that Maryland does require is available at hundreds of privately run gasoline stations and auto service centers. State police visit each station once a month to look at logbooks, and occasionally bring in an undercover car to check the service.

The District didn't want to use gasoline stations either, fearing cronyism and a shortage of monitors to ensure compliance, according to spokeswoman Schanolia Barnes. That explains the use of only two stations, and the periodic long lines.

Mayor Sharon Pratt Dixon is looking into this. "I know of no other public service that we deliver that frustrates more of our citizens than the Bureau of Motor Vehicle services," Dixon said. She promises changes.

State police 1st Sgt. Joseph A. Weathersbee, the Northern Virginia safety honcho, said he believes Virginia's is a model program. Lines are relatively short, and state police check each station once a month for compliance. "If inspectors are not pulling tires, I want to know about it," Weathersbee said

One of those in charge of Maryland's safety inspections, state police Lt. Francis Tully, said he believes that his state's system is adequate even though vehicles can go years without inspections. "Some people will take chances, but sooner or later one of our troopers will nab 'em," he said. Bad brakes can be detected when cars pull to one side when they stop, or by metal-on-metal sounds, he said. Last year, Maryland state troopers issued 100,000 safety equipment repair citations, which require owners to fix the problem and notify the state.

Nationally, 20 states and the District of Columbia require auto safety inspections every year, according to the American Automobile Association. Spokesman Rob Krebs said AAA's members want annual inspections. A recent survey of 5,000 members found 61 percent in favor of them, he said.

The National Highway Traffic Safety Administration, a federal agency, also strongly recommends that state inspections be done every year. Agency officials reason that yearly inspections carry the kind of importance that makes "military forces check their equipment prior to battle," which is not a bad metaphor, considering the combat driving on the Beltway.

Hixson said Gov. William Donald Schaefer initially expressed interest in annual inspections, but wanted to look into it further. Now Schaefer is opposed because he doesn't sense much support for it in the legislature, according to his spokeswoman, Page Boinest.

Maryland might do well to look into this matter again, considering the recommendations of those knowledgeable in the field and the support of the District and Virginia governments.

"Thirty-five percent of the cars we look at are considered unsafe, and we look at them once a year; you can imagine what would happen if we let them go on and on," said Virginia's Weathersbee.

If you'd like to send comments to the appropriate officials, they are:Maryland State Police Automotive Safety Enforcement Division, c/o Maryland Motor Vehicles Administration, 6601 Ritchie Hwy., Glen Burnie, Md. 21062.The supervisor at either District inspection station: 1827 West Virginia Ave. NE, Washington, D.C. 20002; or 1001 Half St. SW, Washington, D.C. 20004.Virginia State Police 1st Sgt. Joseph A. Weathersbee, 703-323-4549.

Truck inspections and emissions inspections vary even more between jurisdictions, but this is enough on inspections for today. I'd like to read about any experiences you'd care to share, particularly from motorists who can compare inspections between jurisdictions. Renovation of Farecard Machines Dear Dr. Gridlock:

You recently mentioned that Metro will phase in over the next few years new Farecard machines that will accept the $10 and $20 denominations. Will the new machines also continue to offer the five percent discount? BRADLEY S. LEBOEUF McLean

Yes, you still will get the 5 percent discount on $10 and $20 purchases. But there's been a change since we last wrote about this. Instead of replacing all the Farecard machines, Metro has decided to renovate them. The work will start next February and be completed by February 1993. Right now, there are 49 Farecard machines and 19 Addfare machines that take $10 and $20 bills. After renovation, all 442 Farecard machines and 169 Addfare machines will be able to do that. Plus they will be better able to detect counterfeits and should reject fewer bills. That's the plan, anyway. Keeping Tabs on Potholes Dear Dr. Gridlock:

Most of my driving is in the District. When I see a pothole that is dangerously large or deep, I notify the highway department's pothole number (202-767-8527). The person at that number invariably is pleased to receive the information, and within a reasonable time the pothole is plugged.

What puzzles me is that cruising police do not note such trouble spots and report them. It is common for potholes on Massachusetts Avenue NW, the Glover Street bridge, and Belmont Road NW to become enlarged day by day while those high-density roadways are being patrolled by police.

I am not suggesting that this become a police duty. I am suggesting simply that they should do what any citizen should do: note and report hazardous situations without interfering with their assigned duties.

The same observation goes for faulty traffic lights. FRANK L. DENNIS Washington Dear Dr. Gridlock:

In many stretches of the various bridges I travel, including the Sousa Bridge and long stretches of the Southeast/Southwest Freeway (particularly the part NOT under construction), the lights are out. This can be hazardous, especially in foul weather. Our government officials could render a great service to us all by making sure that street and road lights are adequately equipped with working bulbs. Wouldn't it also be nice if police officers reported inoperative street lamps. JOSEPH C. FENRICK JR. Capitol Heights

D.C. police do routinely report potholes, damage to sidewalks, malfunctioning traffic signals and street lights that are out, particularly the high-intensity anti-crime lights, according to Daniel Straub, a police spokesman. Straub said his own car suffered $1,250 damage when it fell into an enormous pothole ("swallowed the front of the car") on Kenilworth Avenue last year (he reported it). Suburban public works officials say they receive reports from state police on such matters, and are grateful to get them. These officials continually say they count on the public to help monitor such problems.

The numbers to call in the District are 202-767-8527 for potholes, 202-727-5876 for malfunctioning traffic signals and 202-939-7100 for street lights that are out. If more people called these things in, theoretically, there would be fewer of them. That assumes that the city fixes them promptly. If you make such reports and nothing happens for some time, drop the doctor a line.

Local officials, by the way, are looking for less pothole damage this year because the mild winter produced fewer freeze-thaw cycles than in other winters. Spring is the time they start cropping up, though, so watch out.

Dr. Gridlock appears in this section each Thursday to explore local transportation matters. He'll try to find out why bad situations exist and what is being done about them. You can suggest topics by writing (please don't phone) to DR. GRIDLOCK, The Washington Post, 1150 15th St. NW, Washington, D.C. 20071. Please include your full name, address and day and evening phone numbers.