Wildlife officials are concerned that black bears coming out of hibernation are showing up in alarming numbers along the Sea to Sky Highway near Whistler, B.C.

Part of the problem is clover planted on the roadside when the highway was expanded before the 2010 Olympics. Bear experts say the animals love clover and will brave fast-moving traffic to get it.

"Its dangerous for bears," said Dawn Johnson, program co-ordinator with the Get Bear Smart Society. "They're attracted to the roadside, putting themselves at risk of a collision with a motor vehicle."

Bears have no appreciation of basic safety around motor vehicles, said Johnson.

"If there's a food source on either side of the road — a bear will likely cross the highway," she said. "They don't know to look both ways before they cross."

Ten-fold increase

In 2010, 10 bears were killed by vehicles along the 100-kilometre Sea to Sky, up sharply from an average of one bear per year in previous years.

A bear roams by the Sea to Sky Highway north of Vancouver Friday. (CBC) The roadside grazing is not only dangerous for the bears. Drivers are suddenly slowing their cars so they and passengers can get a better look at the wildlife, causing so-called "bear-jams" on the busy highway, the main route between Vancouver and Whistler.

"It was right on a corner," said Whistler tourist Jen Lucas, who had to slow down quickly for a bear-jam. "There were four or five cars stopped right there… It was not a good spot for anyone to be stopped."

The B.C. transportation ministry has posted signs discouraging drivers from slowing or stopping to view the bears.

The ministry is also considering "roadside vegetation alterations" to deal with the clover, according to the Get Bear Smart Society.

With files from the CBC's Aarti Pole and Alan Waterman.