Image Recognition
"Most U.S. city governments know very little about their sidewalk networks. The paper, "Mapping the Walk: A Scalable Computer Vision Approach for Generating Sidewalk Network Datasets from Aerial Imagery," appears online in the journal Computers, Environment and Urban Systems. "You would drive to an intersection and then the road just ends. "The whole world of urban data for public transit and pedestrians and bicycles is really far behind [vehicle data] in quality. To make best use of pedestrian infrastructure, it's important that cities have the network data about it.