Chouleang Chov, a student at the South Dakota Rehabilitation Center for the Blind, works on his ability to cross a street with a white cane as Bob Smith, an orientation and mobility instructor at the Rehabilitation Center, walks behind on Wednesday, April 9, 2014, in the skywalk over 11th Street in downtown Sioux Falls. Smith said that the skywalk over 11th Street provides a safe, warm place out of the elements to learn to walk safely across the street. (Joe Ahlquist / Argus Leader)