ROCKVILLE — — The Intercounty Connector isn't finished yet, but already the new six-lane highway across the Washington suburbs is drawing traffic — beneath it.
Deer hoofprints and tracks of raccoons and other small animals traverse the soft dirt floor of an oversized stream culvert under an almost completed stretch of highway near here. It's one of 10 wildlife crossings being installed along the 18-mile, $2 billion transportation project.
Crews are still putting the finishing touches on the western half of the ICC, which is to open in early 2011, weather permitting. The animals aren't waiting, though.
"The deer, the raccoons and opossums, they've been going through these culverts long before they had to," said Robert E. Shreeve, who oversees work to mitigate the environmental impact of the highway project. "Suburban animals are not shy."
Even so, they aren't very savvy when it comes to crossing highways. Roads are death traps for animals, and sometimes for motorists, too, when they hit a deer or swerve to avoid one. To cut down on the carnage, state highway officials are trying to pinpoint "hot spots" where deer are frequently hit, so they can post warning signs and take other precautions. Maryland authorities are also trying to get more animals to cross roads safely — often by going under them.
Nationwide, a million or more animal-vehicle collisions occur annually, government and insurance industry data show, and the problem is growing. More than 200 Americans die each year in what are mostly single-vehicle collisions with animals, double the toll in the early 1990s.
In Maryland, about 1,500 animal-related crashes are reported annually, according to state police, but that represents only a fraction of the total. The State Highway Administration says its crews picked up 6,600 deer carcasses along Maryland roads in 2008, the most recent year for which figures are available. That tally does not include animals that were hit and later died off the roads.
At least one fatality and more than 200 injuries to people occur each year in animal-vehicle crashes in the state. Danger is at its peak in November, when deer are breeding, but collisions occur year-round. In September, a Glen Burnie motorcyclist was killed and his passenger injured when they ran into vehicles that had braked suddenly to avoid a deer.
Most collisions with wildlife are not fatal, but hitting a deer can be costly nonetheless. The average repair bill is nearly $3,000, according to the insurance industry, which says it pays $1 billion a year for property damage and injury claims in vehicle collisions with wildlife.
"It's a big expense to run into a deer," said Shreeve, who lives in rural Carroll County, where deer abound. "I've hit three of them," and repairs came to about "$300 per pound" of deer hit.
State officials tried putting in culverts for wildlife when building Interstate 97 south of Baltimore in the early 1990s, with mixed results. The large, corrugated metal pipes used then proved awkward for deer, officials say. Now, the state is making a renewed effort to separate wildlife from traffic.
The highway agency has compiled a database of animal-vehicle collisions, drawn from state police reports and the locations of deer carcasses collected by road crews. From that, officials can pinpoint hot spots where deer get hit often and plan countermeasures.
One such spot is in Pikesville near the junction of Interstate 795 and the Beltway. Deer hazards abound in Harford County, especially along U.S. 1, where data show at least a half-dozen clusters of animal-vehicle collisions in 2010.
The state also wants to see whether existing drainage culverts can be augmented to encourage or more wildlife to pass through. Biologists at the University of Maryland's Appalachian Environmental Laboratory in Frostburg have been monitoring more than 200 pipes and concrete culverts statewide, posting motion-activated infrared cameras in them to capture animals moving through.
"Sometimes the most interesting photos are of people," said J. Edward Gates, the UM wildlife ecologist leading the study. "We've got one guy kayaking through, one guy riding a bicycle through a culvert, people just hanging out in them for whatever reason."
But plenty of wild animals are getting caught on the critter-cams, too — raccoons, deer, groundhogs, skunks, snakes, foxes and even great blue herons.
Preliminary results suggest that deer prefer larger, box-shaped culverts. But larger openings, placement along a natural trail and a dry path through the tunnel might also matter.
The lessons learned will be applied when installing new or replacement culverts, so animals feel more comfortable scurrying through, rather than taking their chances crossing the road.
That's already been done with the ICC, the state's newest large highway project. Planners arranged to install oversized culverts along natural wildlife corridors — stream valleys and established deer paths.
One culvert that has seen use by animals is 17 feet high and 47 feet wide, with Mill Creek, a small tributary of Rock Creek, flowing through one side. Much of the culvert is dry, covered with stone dust and gravel. Larger rocks lie along the walls, allowing smaller animals to dart from the shadows of one boulder to the next. Trees and shrubs were planted at the mouths of the culvert, so animals have cover while approaching or leaving.
"It's amazing how adaptive wildlife are," Shreeve said, "as long as they've got the essentials."
Tall fencing along the highway will give wild animals wanting to cross no choice but to go through the culverts.
Officials also are beginning to take precautions on older highways. The state has erected tall fencing along a stretch of Interstate 68 near Friendsville in Western Maryland, and posted signs warning motorists about wildlife in other spots where there have been multiple crashes in recent years.
The measures are meant to cut down on collisions with black bears as well as deer. Last year, 43 black bears were hit by vehicles, while 68 were shot by hunters, according to the Department of Natural Resources.
If the fencing near Friendsville reduces animal-vehicle collisions, state crews might put up more along I-68, said William Branch, an analyst in the SHA's environmental design branch.
Such measures can seem like luxuries when government budgets are squeezed. Fencing off just 3.5 miles of I-68 cost $878,000. Installing oversized culverts like the ones on the ICC can cost $500,000 or more each. In Montana, where motorists must contend with the likes of elk and grizzly bears, officials spent $1.8 million to build a dirt-covered animal overpass on one accident-prone stretch of highway near Missoula.
"It's not a cheap proposition," acknowledged Gates, the UM wildlife ecologist. But he said the costs should be weighed against the potential deaths, injuries and vehicle damage from collisions with wildlife. "What's a human life worth?" he asked.
Beyond human safety, some suggest it's the price to be paid if society wants to keep wild animals in a landscape increasingly crisscrossed with roads.
"It's about how you value wildlife," Shreeve said.