In the back of a busy highway department depot near BWI Marshall Airport, sign makers tell Maryland motorists where to get off.
And lots of other things.
The State Highway Administration sign shop fabricates 8,500 to 9,500 signs a year, enough metal and plastic to cover a RavensVision end zone video board more than 35 times.
The SHA shop isn't the only traffic sign maker in Maryland, just the biggest and busiest. It provides signs for 28 state maintenance shops, other state agencies and municipalities.
"We're quick. We have to be," said Eugene "Sonny" Bailey, the operations manager who has been putting one letter next to another since 1982.
The fabricators can make one huge sign — like the 30-foot-long one that spans Interstate 270 in Montgomery County — or a city's worth of red octagons with white letters that command motorists to stop. Overnight, they can create a batch of signs to warn of high water when a brute of a storm like Sandy blows into town.
Signs have improved a lot since Bailey came on board. Made of aluminum instead of steel, they are lighter and more durable, lasting an average of a dozen years. The letters are easier to read, and in many cases the background is made with a reflective material called Diamond Grade 11 that returns nearly 60 percent of available light to drivers.
Paul Stout, the SHA's assistant division chief for traffic operations, said the agency collaborated with the Federal Highway Administration in 2002 to test a new typeface, or font, called Clearview.
Clearview, developed by traffic engineers from Pennsylvania and Texas, replaced a font used since 1949 called, appropriately, Interstate, according to Simon Garfield, author of the book, "Just My Type." The Interstate font was so popular and useful for speed reading that it was adopted by Southwest Airlines and the Weather Channel.
But with its taller lower-case letters and greater space in the interior of each letter, Clearview improved legibility by taking into account all driving conditions, especially "for night vision, poor weather and the needs of the elderly," Garfield said.
Since 2005, ClearView has been the standard font on all white-on-green interstate signs.
Highly reflective signs reduce the need for spotlights, saving money and reducing light pollution, Stout said.
In most cases, Maryland signs conform to federal standards. The shop has a book that covers dimensions and layout for everything from crossings for the disabled to carpool lot signs.
For small batches of signs, today's fabricators eschew the artists' knives and T-squares of yesteryear in favor of computer-assisted layout to ensure the spacing and size are by the book.
Signs are made by pressing reflective vinyl film onto aluminum sheets, creating a long-lasting bond. Excess material is peeled away. Once applied, it is impossible to remove the material without destroying the sign, Stout said.
When the SHA needs large quantities, the shop uses a silk-screening machine that can churn out 500 signs a day.
For Jeff Wilderson, that meant he spent one recent shift sliding aluminum blanks into a machine and activating the squeegee that forces ink across a stencil that says: School Bus Stop Ahead.
Once the message is delivered, the wet sign is placed in a rack and wheeled into a drying room overnight to set. A two-color sign will be run through the silk-screen process again.
Next door is a room filled with the stencils, or frames, as they are called.
"Your Stop signs and Do Not Enters and your Keep Rights that sit by the side of the road — they always get hit. They're always in demand. They move quickly. We just pull out the frame, make up a batch and restock," Bailey said.
Most signs aren't decommissioned so suddenly by the vehicles they're supposed to direct. More typically, sunlight fades colors and degrades the material over time.
"South-facing signs fade faster than north-facing signs," Stout said. "Kids with paint guns don't do us any favors, and neither do guys with guns."
Old signs don't die.
Stout and his staff always are on the prowl for vintage signs made of riveted steel or ones promoting long-ago locations such as Friendship Airport.
"We found a yellow stop sign. I had my guy go replace it with a red one and we brought it back here," Stout said.
A warehouse holds the signs until they are needed for museum displays and school tours of the sign shop or lent to TV shows and movie sets.
Even those without a pedigree have their place.
The SHA recently donated more than 5,000 linear feet, or approximately $6,000 worth of aluminum, from old road signs to the Department of Natural Resources to build a complex of greenhouses, a native tree nursery and a 5,000-gallon water storage unit on the campus of Frostburg State University.