Dear Dr. Gridlock:

I’d like to add another thought to your discussion of the failure of drivers to use turn signals. Many drivers who do signal don’t turn them on until after they brake for the turn. This isn’t helpful in indicating to following drivers what one’s intentions are. I always use my turn signal in advance of braking for the turn.

Joy K. Reynolds, the District

DG: That reflects good planning. The District driver’s manual says a motorist must use a signal for at least 100 feet before making a turn and urges doing so for a much longer time and distance at higher speeds.

But how often do you see that?Drivers should maintain safe following distances so they’ll have time to react to unexpected movements by the vehicle ahead, and we should pay attention to brake lights without awaiting further developments. That said, it surely helps to have the driver ahead conveying as much information as possible.The following driver probably will react differently depending on whether the lead driver is going to slow and possibly stop or pull to the right or left. Drivers in adjacent lanes might react differently, too.On city streets, the early use of a car’s right turn signal might be a vital warning to a bicyclist on the right side of the roadway who is planning to ride straight through the intersection.

SIGNS’ sight lines

Dear Dr. Gridlock:

One way to reduce the number of traffic accidents and the resultant delay is to improve sight distance.Many minor accidents and fender benders are caused by poor sight distances at intersections and entrances because shrubbery and plantings restrict the view of approaching vehicles, pedestrians and bicyclists.To improve traffic safety, all plantings at street corners, shopping center entrances and driveways should be controlled. Also, on the interstates, many times it is difficult to see entering traffic on ramps because of visual obstructions by bushes and trees. In some cases, the view of traffic signals and signs are restricted by branches.Trees planted in the center island at a curve in the road restrict the view of a red light, and the stopped traffic and does not permit sufficient time to slow down.

Rudolph F. Gaum,
Montgomery County

DG: The Montgomery County Department of Transportation takes care of mowing, pruning and trimming for safety along county-maintained roadways. A traveler who sees a visibility problem that hasn’t been addressed can report it by dialing 311 to report it to the county’s call center. The Maryland State Highway Administration takes care of similar problems on numbered roadways.

The best way to report a maintenance issue to the SHA is to visit and click on “Contact Us” on the left side. There’s an online form to describe the issue. A list of all SHA maintenance shop phone numbers is also on the site.


Dear Dr. Gridlock:

I was planning to meet friends in the District for dinner and wanted to see how long the trip from the Greenbelt station to Dupont Circle would take. Metro’s Web site gave me three options:1. Green Line to Gallery Place, and then take the Red Line toward Grosvenor.2. Green Line to Fort Totten, and then take the Red Line toward Shady Grove.3. Green Line to Fort Totten, and then take the Red Line toward Grosvenor.Now, Nos. 2 and 3 can’t both be correct.

Steve LaBash, Laurel

DG: This is an interesting feature of the Trip Planner feature on Metro’s Web site that I hadn’t noticed before LaBash pointed it out. All the information he received is correct, but it’s confusing if you don’t ride the western part of the Red Line regularly.

Shady Grove is as far as a rider can go in Montgomery County on the western end of the Red Line. At certain times, however, some trains are scheduled to turn back at the Grosvenor station, long before they reach the western terminal. Outbound commuters on those trains must get off at Grosvenor and wait for a through train. Meanwhile, the train they just got off is sent back down to increase service at the most crowded stations in the core of the line.The Grosvenor station is well past Dupont Circle, so any of the three Red Line trains listed — whether the destination sign read Shady Grove or Grosvenor — would have gotten LaBash to dinner.A tourist or an infrequent rider would be unlikely to know that. Consulting a train system map would show the location of the stations but wouldn’t explain what was going on with the trains. The new Metro map eliminated the little text bubbles that explained turnbacks.