The D.C. Department of Public Works is planning to do survey work from July 27 to Aug. 8 on the Frederick Douglass Bridge, a week later than the dates given in the Dr. Gridlock column in today's Metro 2 section. The work was postponed after the preprinted section containing the column went to press. (Published 7/17/87)

Dear Dr. Gridlock:

On June 26, my letter was included in your column. Under the heading "Despicable Spitter," the account of my recent encounter with a messenger biker {who spat on me} was printed in detail.

It struck me as quite ironic that this particular account, Episode One as it might be called, could not even be printed before Episode Two had occurred.

On June 24, I was leaving a parking garage on M Street NW. M Street is a one-way street between 24th and 25th streets. After looking for pedestrians and then looking to the street, particularly to the right from which traffic would be approaching, I proceeded into the street because there was no sign of traffic. Immediately upon pulling out of the garage I nearly collided with a messenger biker who was speeding up M Street going the wrong direction. (He had approached from behind a parked truck.) Would you believe it? It was the same messenger biker who had played the central role in Episode One. I believe we both recognized one another.

He began with abusive language. When he approached my car I asked him why he would not follow the rules of the road, and I stated the he could have been badly hurt. The biker said that he was free to ride as he liked and once again began threatening. I stepped out of my car and he struck me in the face. While I was sorely tempted to return his blow, I informed him that my faith restrained me from hitting him and, at the same time, I observed witnesses standing nearby. The biker appeared surprised at my restraint but obviously upset that others were watching the display. He ran and got on his bike and left.

Lest anyone think that being Christian means being a doormat, or if it seems doubtful that such an encounter could occur again, one may check with the 2nd District Police where I filed a report on this incident.

When will the city council enact legislation which will give the police department muscle in dealing with these violators? THE REV. KENNETH A. BASTIN Washington

Help may be on the way. Responding to a number of complaints about the dangerous behavior of bicycle couriers, D.C. Council member Nadine P. Winter (D-Ward 6) introduced the Commercial Bicyclists Licensing Act three days ago. The bill would require the licensing of commercial bicyclists, force them to take a safety test and to wear identification issued by the city. Winter's bill also would require courier companies to devise training programs for their employes.

The bill was referred to the council's Committee on Public Works, which Winter chairs. The committee may hold a public hearing after the council returns from summer recess on Sept. 29. The committee will then vote on the bill then it would be referred to the full council for action.

According to an aide to Winter, only the provisions about licensing the commercial bicyclists and requiring their companies to devise training programs are firm. The bill is then subject to mayoral review. It is up to the mayor to determine who would enforce the law and what penalties would be set for violations.

Winter's aide said the bill came about with the help of the D.C. Bicyclists Advisory Council. Crawling Over S. Capitol Bridge Plates of Metal Dear Dr. Gridlock:

Every day it's the same problem -- cars slowing down to a crawl to go over two to three metal plates in the middle of the {South Capitol Street} bridge. How much longer before they repave that area? SHARIE CENTILLA Clinton

Unfortunately, those steel plates will be around until next spring, according to Tara Hamilton of the D.C. Department of Public Works.

Hamilton explained that it isn't a matter of simply repaving the bridge, which is also known as the Frederick Douglass Bridge. The problem is that those steel plates are covering cracks in the grates of the drawbridge there. The D.C. government plans to replace the grating during a 30-day period next spring while keeping some lanes open during rush hour.

In the meantime, the Department of Public Works would like to alert motorists about survey work that will occur on the bridge July 20 to July 31. Two lanes will remain open inbound and two lanes will be open outbound during the day, but between 8:30 p.m. and 5:30 a.m. the bridge will be closed. Hamilton suggests that drivers use the 11th Street Bridge during these hours. Here Are Traffic Lights But No Intersection Dear Dr. Gridlock:

The city has installed a set of traffic lights on Benning Road just before the Benning Bridge to Minnesota Avenue {or just under the bridge to Kenilworth Avenue}. Since this is not an intersection, and there is no cross traffic, one wonders just why traffic lights were placed at this particular spot.

I travel this route daily and see the consternation on the faces of other drivers when this light shows red. Some stop; many do not. I confess that since I am going across the bridge, I drive in the far left lane and continue my trip since it appears that the light is there for traffic going under the bridge rather than over it. However, I am not sure about this and would prefer not to be caught in an illegal situation.

Is there any way to check and see what purpose this light serves? And more importantly, is there a way to notify drivers that they need to stop if going under or over the bridge, or both. H. JONES Washington

George Schoene, chief traffic engineer for the District, agreed that the arrangement of the lights at the Benning Bridge was confusing. He said the "offending signal has been removed."

The signals were installed at the bridge to get pedestrians and bicyclists across the service road that runs parallel to Benning Road and over the Kenilworth Avenue ramp. But, he said, there were three signals where only two were needed to move traffic off Benning Road onto Kenilworth Avenue.

Schoene reports that the confusing light was taken down and the remaining two lights repositioned so that it is now clear to all drivers that the lights are only for traffic leaving Benning Road.

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.