Dear Dr. Gridlock:

A car's life span depends on how it is used or abused. The oil will keep the engine clean, but frequent short trips will overload the oil's detergents with water, acids and other byproducts of combustion.

A poorly tuned engine might dilute the oil with unburned fuel. On longer drives, the oil gets hot enough to evaporate some of that.

Hard engine use when the oil is cold will cause increased wear. The interval between oil changes should be adjusted to the vehicle's usage, and generally when the oil looks really dirty, it's time for a change.

Manufacturers' recommendations are based on worst-case driving.

Bill Seabrook


Parking Meter Trickery?

Dear Dr. Gridlock:

Around 6 p.m. on a recent day on 25th Street NW in the District, I watched a man park in a metered spot, place a plastic bag over the meter and proceed into a building. He was in the building for at least 15 minutes.

I had many thoughts about how he was trying to trick parking enforcement. Then I wondered whether he was a food delivery person and this was an acceptable means of identifying himself to ticket writers. Do you have any insight?

Ryan Grover


I've never heard of this, and neither has Bill Rice, spokesman for the District Department of Transportation, which has jurisdiction over parking meters. Does anyone else have any thoughts?

Laggards Not Tolerated

Dear Dr. Gridlock:

I have no problem stopping for a school bus that is discharging or loading kids; it is the law.

I do, however, have a problem with the kids. On my way to work, I have had to stop for a school bus, and the kids just take their sweet time walking to the bus.

On most occasions in the morning when they are loading the buses, the kids just saunter toward the bus as if they have all the time in the world, not caring about the drivers they are delaying. After a few minutes of this insanity, I find the car horn on the steering wheel! Enough is enough.

I think the school system should educate kids to be more considerate of those they are inconveniencing. After all, assuming that a motorist doesn't run them over out of anger, they will one day be behind the wheel of a car on their way to work.

James Evans

Silver Spring

If a stopped school bus is using its flashing red lights, motorists have to stop. If the bus is slowing, flashing yellow lights signal caution. I'm not sure what the status of the bus is when you are encountering the described loafers.

I would say generally that you should respect their loading and unloading process, even if it seems slow to you, and the students, of course, should be mindful of traffic needs. If this is a constant problem, another route might make sense.

Eating on Metro

Dear Dr. Gridlock:

Wow! People are so afraid that they fear speaking to eaters on the subway [Dr. Gridlock, June 23]! When I see Metro riders eating or drinking and I am near them, I always tell them it is forbidden.

Most are tourists who immediately put the food away. No one has ever told me to mind my own business or has gotten nasty. Quite the opposite: They thank me.

I always mention the incident of the young girl who got arrested for eating french fries a few years ago.

In defense of innocent eaters, Metro does very little in providing large signs for all to see easily. On the ends of the trains there's a small sign advising what is not allowed. Metro should place larger signs throughout the trains if it is really serious about this rule.

Linda M. Cajka

Lake Ridge

I agree: Metro can do more to warn riders that it is illegal to eat or drink on the system.

Dear Dr. Gridlock:

Metro's overreaction regarding its policy about food made headlines last year when a customer was arrested for finishing her snack as she entered a station.

Imagine my surprise at the situation I encountered when I took the Red Line from Glenmont to Union Station on a recent Monday. Sitting on the train was a teenager sipping a big can of fruit juice. Across from him stood a Metro employee in uniform, watching. That continued for several stations, until the employee left the train.

The policy is enforced in some cases, but not in others.

Sonja Dieterich


In such a case, get the employee's name and report the incident to Metro at 202-637-1328. Metro should launch an inquiry and caution employees to warn offending passengers.

Lesson From Paris's Metro

Dear Dr. Gridlock:

I recently had the good fortune to spend a week in Paris and used its Metro frequently. The solution there to seating near the doors seemed quite intelligent.

There were eight hinged seats near the doors that were used when the car was not crowded. When a large group entered, the people on those hinged seats stood up, making room for the other passengers.

When it became less crowded, they sat back down. It worked well and provided flexibility within the cars.

Cathy D. Knepper


Spokeswoman Lisa Farbstein said Metro considered the Paris model but decided not to use it. Seems as if it might have been useful here.

Relief Near on N. Capitol St.

Dear Dr. Gridlock:

What is going on with the never-ending construction on North Capitol Street north of Michigan Avenue? Will it ever be over? The multiple unpredictable lane changes are really confusing and are not well marked in advance.

Allan Glass


The project should be completed by the end of the summer.

The city began the 18-month reconstruction of North Capitol Street, from Michigan Avenue to Harewood Road NE, in December 2003. It is on schedule, District Department of Transportation spokesman Bill Rice said.

The project includes resurfacing; new sidewalks, curbs, gutters and streetlights; and the reconstruction of two bridges.

Red-Light Transgression

Dear Dr. Gridlock:

Recently I received one of those automated "notice of infraction" mailings with three color photos of the south end of my car headed through an intersection in front of Washington Hospital Center. It had all the details of my transgression and a form to complete.

Ouch; they got me.

But before I mail in my check, consider this, just for perspective.

In this town, where professionals account for time in hours and years, that 0.4-second $75 infraction works out to an hourly rate of $675,000, or an annual rate (assuming a 2,000-hour year) of $1.35 billion.

We read about high-paid lawyers and lobbyists in this town, but we'd be hard-pressed to find one commanding those rates.

Where does this money go? Well, I got a slick notice. And it must have been approved by roomfuls of traffic enforcement representatives, lawyers, graphic arts professionals, computerized optical instrument geeks, equipment providers and consultants. So we can figure they got their cut.

Is Washington safer? Does traffic flow better? What about the octogenarian diabetic I was taking to her 10 a.m. appointment at Washington Hospital Center; how is this going to help her?

It won't take too many more of these "gotchas" to discourage me permanently from volunteering this kind of help in the District.

Paul Slattery


Thanks for your unusual take on a red-light ticket. But the fact is, wherever cameras catch and ticket red-light runners, red-light running at that intersection has declined dramatically. I'm all for them. Drivers should not run red lights.

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, or faxes, at 703-352-3908. Include your full name, town, county and day and evening telephone numbers. Dr. Gridlock cannot take phone calls.