Dr. Gridlock has received several complaints recently about people standing in the middle of the road at 23rd Street and Constitution Avenue, and also on Key Bridge. Some of these people are panhandlers and some seem content to curse and knock on windows. Here is one such letter: Dear Dr. Gridlock:

For the last few weeks on my way home to Bethesda, from Virginia, I have encountered various men who are panhandling on the Key Bridge. I really mean "on" the bridge. Last night, one man was walking up and down the double yellow lines with a teddy bear under one arm and a "collection" cup in his other hand, with rush-hour traffic zooming within a couple of feet on either side of him.

As you may know, those turning left off the bridge (toward Canal Road) are hell-bent to make that light as only a few cars can get through each time. Luckily (I thought), I spied a D.C. motorcycle policeman at a gas station just after I turned, and I told him about the man on the bridge. He said he already knew about it, and there was nothing he could do. I was speechless and drove on.

This morning I called the department's community relations unit with the problem and was told that the officer was correct because there are no vagrancy laws in D.C. I protested and said that this situation would seem to be covered under ordinary traffic law that prohibits pedestrians, tractors and bicycles from thoroughfares except, in the case of pedestrians, on the pedestrian walkways. I was then referred to the 2nd District station and, in turn, to the supervisor's office, and in turn, to the Sector 2 sergeant, where I was cut off and gave up.

So I am turning to you. I feel this presents a very dangerous situation for everyone and could lead to tragedy. What's the deal? KAREN SALISBURY Bethesda

First, the law. Vagrancy has nothing to do with it. According to information supplied by Officer Edward Wilson, a police spokesman, Title 18, Section 2305.2 of the D.C. Municipal Regulations says, "Where sidewalks are provided, it shall be unlawful for any pedestrian to walk along and upon an adjacent roadway." The fine for violating this is $5.

Wilson suggested that citizens report such concerns to the station clerk at the police district in which the offense is noted, in this case, the 2nd Police District. That would cause the matter to be logged in and brought up for special attention at roll call.

When I called, though, I had the same problems you did. The station clerk said he was not the person to take such a complaint, and referred me instead to the Sector 2 sergeant, who referred me to the police non-emergency communications number, where a person referred me to the 2nd District desk sergeant, who agreed to take a complaint while noting that if I had called in the daytime he would have referred me to yet another number.

Washington, D.C., has, for its population, a very large police force. The effectiveness of this police force in dealing with traffic offenses, such as intersection blocking, red-light running and double-parking, can be seen downtown. You would think, though, there at least ought to be some simple procedure for taking complaints from the public.

Not that a $5 fine is going to deter someone. "We run them out of there all the time," said the desk sergeant, Officer Leonard Gooch. "All we can do at most is a $5 fine."

We hope no one will be killed. If he continues to be a problem, please keep writing. And if you have trouble getting police to take complaints about anything, please note the specifics, including the names of people you talked to, and drop me a line. Police should know that what we both encountered while trying to report a concern is a systemic problem. Scofflaw Cyclist Dear Dr. Gridlock:

Here is the scene: Westbound on Hunter Mill Road in western Fairfax County, stopped for the light at Vale Road. A bicyclist dodges around cars and passes the light while it is clearly red. I could see red and saw red!

As I passed the cyclist, I opined that he should obey the lights. Whereupon he opined, via hand signal, that I should soak my head. Whereupon he immediately ran the next red light! The end? Oh, no.

As luck would have it, there were two Fairfax County police officers, each in his very own cruiser, not a quarter of a mile from the last light. I stopped and informed the officers of the cyclist's transgressions. One officer thanked me and stated, "We'll take care of it." I moved away, smug in my belief that the offending cyclist was about to be chastised by the local constabulary when, in disbelief, I watched in my rear-view mirror and saw the cyclist pass the police and continue on his merry and law-breaking way.

I'm at a loss. What do we citizens do? JOHN DRAKE Springfield

About all you can do is note the names of the officers, or their cruiser numbers, and write to the chief of police. That ought to get the matter looked at. The officers in this instance may have a view that makes their conduct understandable. Then again, maybe not.

We can't make police want to enforce traffic laws more, but we can encourage them to do so. Chronic Blockers Dear Dr. Gridlock:

I have written to the Bureau of Parking Services, (65 Massachusetts Ave. NW, Washington, D.C., 20001) as you have suggested to make them aware of chronic double-parking and blocking lanes that are supposed to be open for rush-hour traffic on:

19th Street NW between Dupont Circle and K Street.

21st Street NW between M and K streets.

24th Street NW between N Street and Pennsylvania Avenue. VIRGINIA BABIN Arlington

Please write again in a month and advise me if anything has changed. Dear Dr. Gridlock:

On First Street NW, people think nothing of suddenly stopping on a two-lane street so they can pick up friends or family. Needless to say, those stuck behind these clods have to wait for the oncoming traffic to clear to go around. This problem is NOT addressed adequately by the city, in my opinion. NANCY DANIELS Alexandria

Isn't it astounding how many people seem oblivious to the needs, not to mention the rights, of others? Where are the police? Just last Wednesday morning, the doctor observed a D.C. police cruiser parked on I Street NW, near 16th Street, with an officer sitting in the passenger seat, apparently waiting. Directly in front of him were several vehicles double-parked, narrowing the street from four lanes to one. Maybe the officer was on an emergency of some sort. Maybe not. What is certain is that if double-parking is frequently allowed, it will frequently happen. Animals Underground Dear Dr. Gridlock:

Are there any humans with feelings out there?

I recently had a frightening experience on the subway. I was coming up the Dupont Circle escalator with hands full and tripped. I was three stairs from the top and fell just above the escalator. I managed to cut my knee open on the stairs and bang my head on the handrail before hitting the ground.

I was initially stunned and found I could not bend my knee in addition to blood running all down my leg. When I attempted to stand up, I was unable to find something to hold onto and pull myself up, so I laid there hoping for some assistance.

People stopped, stepped over me and then turned around to stare. Not until about 10 people had walked over me did some little woman, half my size, stop and help me get up.

I am appalled at the rudeness of people on the subway. It is bad enough to push people waiting to get on the subway, but to step over and ignore an injured person is not only frightening but a prime example of how animalistic our society is becoming. KAREN MAXEY Lothian, Md. In smaller towns, hopefully this wouldn't happen. With the stress of life here, it seems too often easier to focus on ourselves, rather than others. Yikes, the theme of the column unfolding today seems to involve inconsideration. Read on.

Dear Dr. Gridlock:

On Monday, July 30, my husband and I were stopped in traffic for an hour on eastbound Interstate 66 between the Dulles Airport Access Road and Lee Highway. Although we obeyed the signs, many motorists were forcing their way ahead in lanes that were closed for construction ahead; many others were using the shoulders.

I wish to offer an explanation to the driver in the adjacent lane who sarcastically thanked us for not allowing her to get in front of us: drivers who ignore signs and take advantage of these situations do not deserve consideration from those who do follow the rules.

The driver in the proper lane who feels he is being courteous by allowing these line-busters ahead of him is actually being inconsiderate of the drivers in line behind him. There is no obligation to be courteous to inconsiderate, and even dangerous, drivers. R.D. SLOAN Arlington

Amen. Smoky Rest Stop Dear Dr. Gridlock:

How many barrels of oil are these trucks and buses using unnecessarily? Drivers of these vehicles rarely turn off their engines when parked! Every time I pull into a rest stop, dozens of diesel trucks and buses are parked, their engines idling away and belching clouds of black smoke.

The other day I was in a store in Prince George's County for more than one hour. A diesel tractor-trailer was being unloaded at the dock. It was idling when I arrived and was still belching fumes when I left. Why is it these vehicles stand idling so much? RICHARD E. STEVENSON Kensington

A guess would be they are idling to keep the cabs air-conditioned. That doesn't excuse it. We have 4 percent of the world's population and use 25 percent of the world's oil. That party may be coming to an end. Maybe some truckers can enlighten us as to why engines are left running . . . . Red-Light Runner Run-Up Dear Dr. Gridlock:

Please include me in the number of people appalled at red-light runners in this area.

Five days a week for 11 years, I have commuted down Massachusetts Avenue to Connecticut Avenue and L Street. I have seen the red-light runners increase alarmingly.

I am fully in support of camera surveillance to stop this dangerous abuse. CLAIRE D. JOHNSTON Washington

I am all for camera enforcement -- the sooner the better! A so-called "study group" is not necessary.

These red-light runners endanger us all. ELEANOR R. McLENDON Silver Spring

I am in favor of camera-prompted tickets for people who run red lights. This silly behavior threatens pedestrians and other motorists to save less than a minute.

Bicyclists (I am a bicycle commuter who obeys traffic lights) also need to be stopped and ticketed.

Short of a fire or a baby on the way, I see no reason for running red lights. VIVIAN M. KELLER Silver Spring

I too would like to vent my frustration at red-light runners and lack of law enforcement dealing with the problem.

I have seen many fender-benders on Keene Mill Road in Springfield because of this. I have been to the Fairfax County Police Department, West Springfield branch, twice to express my concern, and am told they don't have enough officers to enforce this.

I very much would like to see something done about red-light runners. JACQUELINE B. WALDRON Springfield

Nothing new to report on camera enforcement, sadly. The Metropolitan Washington Council of Goverments recommended that area governments consider camera enforcement for red-light runners, but nothing has happened. Not even a test. If anyone has a suggestion to move officials on this, the podium is open. Pedaling a Solution Dear Dr. Gridlock:

Almost no one uses bicycles for transportation because it is too dangerous to share the road with cars and trucks. A network of bikeways would serve everyone for local travel and commuting.

Because they are narrower, fit between and around existing buildings, alongside existing roads and rights-of-way, do not require traffic signals and so on, bikeways cost far less than even the most minor street.

Many people would bike to work if it were within six or eight miles, thus cutting down on car traffic. It is better for your health and does not pollute the air or consume gas or oil.

And it's far cheaper than driving.

Eventually, all our communities are going to have to offer a mixed-use transportation network, combining rail and trolley, subway, bicycle, pedestrian, truck and automobile ways.

Financing? Easy. Gasoline here is so cheap compared to most of the industrialized world. A nickel a gallon at the pump would collect -- how much in Northern Virginia and suburban Maryland? $30 million or $40 million?

If Montgomery County can build sidewalks at $27 per foot, a wider path would be how much -- $50 per foot?

Compared to highway costs per foot, bikeways are really cheap! BUD ROBERTS Falls Church

This seems like an idea hard to oppose. We simply can't build roads fast enough to match demand, and the rising cost of oil ($31 per barrel as this is written) is going to make automobile commuting even less desirable.

Alternatives are needed, and it's hard to find fault with a medium that is relatively so cheap to build and to use, to say nothing of the less damaging effects on our environment.

Many West Coast cities are building bikeways into their street system. What do we have to do here to move this along? Final Head Checks Dear Dr. Gridlock:

I share the motorcyclist's concern regarding motorists who change lanes without checking, but using mirrors is not enough. Side mirrors have a blind region to the side and rear in which a motorcycle or even a car won't be seen.

After checking the mirror, a driver should always make a "head check," a quick, direct look to the side -- before starting the lane change. NICHOLAS J. CARRERA Falls Church

Dr. Gridlock appears in Metro 2 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 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.