Multiple Choice, Multiple Answers

Read the passage and select ALL correct options. Wrong selections lose points.

Wildlife crossings, including overpasses covered in soil and vegetation and underpasses built beneath busy roads, are designed to let animals move safely between habitats fragmented by highways. Studies from regions that have installed such structures report significant drops in vehicle collisions with large mammals like deer and elk, along with measurable genetic benefits, since populations separated by roads can once again interbreed. Crossings are typically most effective when paired with fencing that funnels animals toward the structure rather than onto the roadway itself; without such fencing, animals often continue crossing at unsafe points nearby. Engineers also note that different species prefer different structure types, so a single crossing design rarely serves every local animal population equally well.