As a low-slung car traveling about 40 mph clanked and clattered over the worn wooden deck timbers of the Jericho Covered Bridge in Kingsville, Chris Scovill noted wryly about how often the posted speed limit is observed on the structure that connects Baltimore and Harford counties.

"Yeah, right, 25 miles per hour," he said.

As volunteer curator for the Friends of Jerusalem Mill, Scovill keeps a close eye on the historic wooden structure that spans Gunpowder Falls. He can point to the worn spots on the deck, the scorch mark where someone set a fire, the places where graffiti has been painted over.

Yes, the bridge has been through a lot in its 148 years, which, as Scovill notes, is no reason to allow its demise.

Built the same year Abraham Lincoln was assassinated by Harford County native John Wilkes Booth, it survives as one of six covered bridges in Maryland and the only one in Baltimore County. It was placed on the National Register of Historic Places in 1978.

Major renovations were made in 1937 and 1982 and another one is due starting early next year that will shut the bridge down for six months to a year.

Scovill noted that only three of Maryland's six covered bridges are open to traffic. He supports any effort to keep the Jericho as a functioning bridge and not a museum piece.

"We don't want to wrap it in bubble pack. We want the public to enjoy it," he said.

Because of its setting amid the woods and trails of Gunpowder Falls State Park, many assume it is state park property. In fact, the bridge is owned and maintained jointly by Baltimore and Harford counties.

The upcoming bridge rehabilitation project will cost $2 million, mostly funded by a grant from the Federal Highway Administration's National Historic Covered Bridge Preservation Program, along with an $80,000 contribution to be shared by the two counties.

Keith Duerling, an engineer with the structural design section of the Baltimore County Department of Public Works, said the overhaul is now scheduled to begin early in 2014, after being postponed from a fall start. Bids will go out this fall, he said.

"The process is taking awhile: It's a federal and state project," he said.

For the estimated 490 vehicles that cross the bridge daily, a detour during the reconstruction will be Jerusalem Road on the north, Old Joppa Road on the east and Franklinville Road on the south.

The Jericho bridge rehab will follow the model of the 2010 reconstruction of the Gilpin Falls Covered Bridge rehabilitation in Cecil County. The bridge will be stripped to its skeleton and have some major beams replaced, then reassembled and covered in fire-retardant chemicals and an anti-graffiti coating.

When it was built, the 87-foot-long Jericho bridge was a state-of-the-art structure in the era of the horse and cart. It is a Burr arch through-truss bridge — named for its designer, Theodore Burr, of Pennsylvania. His design combines a long wooden arch on each vertical wall attached to king-post trusses, which have been used in bridge building since the Middle Ages.

County Councilman David Marks, whose district includes the bridge, called the wooden span a "historic icon of northeastern Baltimore County."

"It's hard to imagine Kingsville without this beautiful wooden bridge," Marks said. "We need to do whatever we can to protect it from deterioration."

Scovill noted that it's not exactly the same bridge that was built the year the Civil War ended. For one thing, steel supports under the deck, which are visible from beneath the bridge, now bear the weight of traffic. He prefers not to call too much attention to that.

"We don't want to rob the romance," he said.

Covered wooden bridges survive not because they are practical, but because of the aesthetic appeal and their link to a region's history.

The Jericho bridge was constructed to serve commercial interests after the adjacent villages of Jerusalem Mill and Franklinville became busy mill towns when a dam was built on the Gunpowder Falls. Mill owner David Lee II successfully lobbied to have it built to serve the nearby cotton mills, wrought iron works and blacksmith shops. Completed in December 1865, it cost $3,125.

For awhile, the Jericho bridge had a companion covered bridge, the Jerusalem bridge, a half mile away. It was torn down in 1928.

As much of a menace as the speeding traffic that shakes its deck is the threat of fire. Arsonists are the mortal enemies of wooden bridges and the Jericho bridge has had its share of attacks — a scorch mark on the deck is testimony to a firebug's mischief about three years ago.

"For whatever reason, covered bridges suffer this fate," Scovill said. "Flame-retardant paint has saved the life of this bridge many times."

According to legend, another entity attracted to covered bridges are ghosts, perhaps because the interior of a covered bridge is a convenient stand-in for a gallows. A perusal of the Internet reveals various tales of ghosts that haunt the Jericho bridge. Scovill said he has heard stories of "slaves" being hanged there, but he discounts them (slaves had been freed by the time the bridge opened).

A website called The Ghost Seeker devotes a page to the Jericho bridge and says it is haunted by a woman who carries a basket and a little girl who was burned to death.

A researcher, identified only as Glenn on the website, said he spent time on the bridge after dark several nights in 2005. He said he felt something like a pebble land on his foot and heard footsteps. He added that he also heard a scream that lasted 30 seconds before he ended the investigation when park rangers ordered him to leave.

One thing's for sure, haunted or not, the supportive Friends of Jerusalem Mill are not yet ready to give up the ghost on one of the most unique historic sites in Baltimore County.