U.S. 191 that cuts through a piece of Yellowstone near its NW boundary has long been a wildlife slaughter alley (elk, moose, deer, bears, wolves, and human slaughter too). A high tech warning system was installed in 2002, but glitches kept it inoperative, and there was consideration of dismantling it. Now it has got the go ahead.
Of course it is still inoperative.
Story in the Billings Gazette by Mike Stark.