And with a corridor on either side of the road taken out of the hands of the park authorities and given to the highways agency, fencing would almost certainly result, blocking movement of the herds.

BBC: Serengeti road scrapped over wildlife concerns

And then it has two natural barriers: the Denny Street overpass, on one side, and the interstate 5 corridor, on another.

NPR: Homeless Alcoholics in Seattle Find a Home

The extension would improve access from the suburbs through Midtown, the yet-to-be-built Hudson Yards development on the West Side and along the existing No. 7 train corridor into Queens.

WSJ: N.J. Subway Idea Lives