Dear Dr. Gridlock:

I second Michael Ahern's complaint [Dr. Gridlock, June 2] about the Prince William County Sheriff's Office's handling of the church traffic exiting and entering Route 28 every Sunday.

The situation is grossly unfair to drivers traveling through the area, and the rent-a-cops in charge are totally uncaring of that fact.

At a minimum, the officers directing traffic should coordinate their actions with the traffic light intervals visible at the nearby Route 28 and Routes 619/215 intersections, but they don't.

I suggest your readers contact the large church involved. Let's see if the church leaders will require that the officers restore some fairness to the situation.

Richard Wallace

Nokesville

That would be nice. A better solution would be for the county police and sheriff's offices to forbid their officers to be used as rent-a-cops.

If a church is paying them, where do we think the officers' loyalties will lie when directing traffic on Sundays?

CF Sleuthing

Dear Dr. Gridlock:

A black Chevrolet Tahoe SUV with CF (clean fuel) plates was seen last night in a parking lot near Potomac Mills.

There was no indication if the vehicle had been converted to use CNG (compressed natural gas).

If I had a non-hybrid vehicle that had been converted to CNG and could use CF plates, I think I'd advertise just that on my vehicle, so that folks would know it was a legitimate use of the CF plates.

Sheldon Daitch

Dumfries

Why do you believe the vehicle is powered by CNG? As you say, there is no indication that it is. A vehicle could be powered by a number of low-emission and no-emission systems and qualify for CF tags and use of the HOV lanes without restriction.

Virginia does not require a vehicle owner to display what type of power a vehicle has, according to Pam Goheen, a DMV spokeswoman.

More information about this subject is available at www.dmv.virginia.gov.

Good Care or Good Luck?

Dear Dr. Gridlock:

I also drive a car with hundreds of thousands of miles on it (250,000, to be precise), and I can attest that an oil change every 3,000 to 6,000 miles has little or nothing to do with the fact that the vehicle is still running.

Consumer Reports was dead accurate when it said this recommended oil change-frequency is purely a ploy by auto manufacturers to get consumers to cough up more cash in maintenance.

I change the oil approximately every 10,000 miles depending on wear, sometimes as infrequently as every 15,000 miles.

A lot of the reason any particular car lasts as long as it does is not only good care but a healthy dose of luck.

Kyle W. Thompson

Leesburg

I suspect we'll hear from others on this.

Signs Set Straight

In February, Metro's electronic signs began showing when the next trains would arrive at a station. In doing so, Metro stopped giving the length of or number of cars in an upcoming train, information that some customers had relied on to know where to stand on the platform to be near the doors.

After a survey, Metro reinstated posting the length of trains over the Memorial Day weekend.

The new displays indicate the color of each rail line, the number of cars operating in a train, the train's endpoint destination and the number of minutes until a train is expected to arrive, according to Lisa Farbstein, a Metro spokeswoman.

When a train is about 30 seconds away, the letters ARR will appear under the arrival section, signaling that a train is arriving at the station. When a train is at the platform, the arrival time for the train shows BRD for boarding, Farbstein said.

The signs will still display the next three trains coming into the station.

A number of readers wrote to encourage Metro to reinstate the length of train information. You have been heard.

HOT Lanes Site

The Virginia Department of Transportation has set up a Web site to post the latest information on the proposed construction of high-occupancy toll (HOT) lanes on Interstates 395 and 95 between Washington and Fredericksburg.

The state is considering a partnership with the private sector to construct two extra lanes in each direction.

Tolls would be collected via electronic transponders, much as with E-ZPass.

Beginning in mid-July, an advisory panel consisting of transportation experts and policymakers will review the detailed proposals. The meetings are open to the public. Meeting locations and times, and the proposals, are listed on www.VDOT.virginia.gov. From the home page, click on "What's New."

The public can comment by e-mailing HOTlanes@VDOT.Virginia.gov.

Widening of the I-95 corridor still would require an environmental impact study statement. Construction is years away.

Law Enforcement Exception

Dear Dr. Gridlock:

I'm curious what can be done about off-duty law enforcement personnel in unmarked cars using the Dulles Access Road or the HOV lanes on the Dulles Toll Road, with impunity.

One of these cars enters the toll road westbound at Reston every morning, joins the Dulles Access Road briefly, then turns on his emergency lights while making a U-turn on the access road before commuting the length of the access road beyond the Capital Beltway.

This same car (and others) uses the HOV lane during the evening rush hour and exits in Reston.

Others commute to and from a residence in Loudoun County.

These are not unmarked cars on patrol or Dulles airport vehicles, and they have Virginia and District of Columbia tags. I have the tag numbers if you want them.

I also don't accept that they are on any sort of official business. Their point of origin or destination is not the airport.

Under what authority would law enforcement officials be allowed to use the access road to commute between their homes and places of employment?

Leveraging the badge to shorten one's commute is just plain corrupt.

Ray Banks

Leesburg

Law enforcement personnel, on duty or off-duty, can legally use the Dulles Access Road and the HOV lanes.

You're obviously a man with great powers of observation. Why not use those powers to focus on your Board of Supervisors and the rate at which they are allowing development in Loudoun County, one of the fastest-growing counties in the country?

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