Baltimore has erected about 200 new signs on main arteries to mark them as evacuation routes in case a terrorist attack or other emergency requires a mass exodus.
With bright blue circles and white arrows, the signs are supposed to direct people to the quickest ways out of the city.
The city's Office of Transportation put up the signs during the past few weeks as part of a security plan developed after the Sept. 11 terrorist attacks.
The courses mostly follow the city's long-established snow emergency routes - main thoroughfares that lead out of the city to the north, south, east and west.
"We do small evacuations all the time, a fire in a neighborhood [for example]. This sort of brings it out to the next level," said police Maj. Robert F. Biemiller, commander of the department's special operations division.
The signs do not have words or letters, but Biemiller said the design is the "universal identifier for evacuation routes."
The city plans to add a placard to each post with the words, "Evacuation Route," Biemiller said. That portion of the sign is not ready, and the city was eager to put up the part that was done, he said. He did not know when the placards would be added.
"We're just progressing as quickly as we can, and we're far ahead of a lot of other cities," he said.
In the event of an emergency, police officers would be posted at designated intersections to direct traffic out of the city, Biemiller said. The signs are meant to keep cars on the right route until they get to the next officer, he said.
Mayor Martin O'Malley, Police Commissioner Edward T. Norris and city Transportation Director Alfred H. Foxx Jr. showed off the signs yesterday at a news conference on security measures being taken for the Fourth of July.
The security measures include a ban on tanker trucks, tractor-trailers and other commercial trucks in the downtown and Inner Harbor areas tomorrow beginning at 12:01 a.m.
Police, fire, health and transportation officials will staff a command post to monitor the city.
The Police Department also will deploy helicopters, marine units and extra foot patrols at the Inner Harbor for tomorrow night's fireworks display.