Dear Dr. Gridlock:

A perfect use for the electronic signs along major highways in the D.C. area would be to remind drivers to turn headlights on during rain or other inclement weather.

There have been so many times that drivers, particularly Marylanders, have neglected to do so and seem offended if I flash my lights to remind them. It’s a state law that is being ignored.

— Julia Newhouse,


It is indeed Maryland law that drivers must turn on their headlights when they turn on their wipers, and it’s an excellent safety measure to increase visibility in bad weather. D.C. and Virginia ask the same of their drivers.

Among the complaints motorists have about each other’s behavior, failure to obey this rule is in the top five. (The top complaint is about other drivers’ inability to figure out how to merge.)

A reminder on an overhead message board would be more likely to encourage good behavior than flashing your headlights. But David Buck, a spokesman for the Maryland State Highway Administration, tells me that there’s a fairly rigid system of priorities governing the words on those overhead signs.

It’s not like I thought his colleagues sat at computer screens and dreamed up bits of whimsy to share with the motoring public, but I didn’t know that they were strongly discouraged from sending out messages that “don’t relate to real-time travel conditions,” as Buck put it.

The signs are traffic-management devices, and as such, general information — even something we’d think of as related to driver safety — has a relatively low priority compared with specific information about traffic conditions, such as a crash ahead or road work.

It’s not that they don’t do safety messages, Buck said. It’s just that they’re at the bottom of the list and usually involve statewide safety programs. They may be part of coordinated campaigns about motorcycle safety or drunken driving. Amber Alerts about child abductions and Silver Alerts about missing elderly people also are on the list.

Many of us have messages we’d like to add or eliminate. I’d drop the one that says “Report Suspicious Activity” and gives a phone number for you to memorize while driving. I’ve heard from drivers who would like to add, “Don’t cross solid white lines.”

If the message senders took our advice on what we’d like them to say, drivers might feel overwhelmed and annoyed and just ignore the signs. Another risk is that safety messages could make driving less safe if too many motorists slow down to read them and traffic became congested.

With that in mind, the program aims to limit messages to one phrase — and in plain language.

I find the messages stating distances and travel times to be among the most useful information commonly displayed, but some drivers complain that even that easily digestible information causes drivers to slow just before reaching a sign.

As I write this, I’m looking at the information displayed on Maryland’s variable message boards. You can do the same by going to the State Highway Administration’s CHART Web page at

Everything I see conforms to the standards Buck described. “MAJOR DELAYS/I-95 NORTH/STAY ALERT,” one says. Along Route 50, another tells drivers bound for the Eastern Shore, “TWO-WAY TRAFFIC/ON BAY BRIDGE/FOLLOW GREEN ARROWS.” Those already on the Eastern Shore and heading west on Route 50 get to see, “BAY BRIDGE/25 MI AHEAD/28 MIN.”

The most common closing line statewide: “STAY ALERT.”

To read previous Dr. Gridlock columns, go to
. Dr. Gridlock also appears Thursday in Local Living. Comments and questions are welcome and may be used in a column, along with the writer’s name and home community. Write Dr. Gridlock at The Washington Post, 1150 15th St. NW, Washington, D.C. 20071 or