Although the focus of many navigational mapping applications has been on driving directions, pedestrians, runners, and bike commuters perceived high speed thoroughfares as barriers to their ability to navigate the city. In addition, major roadways are often perceived as psychological barriers that people do not want to cross and that cut off sections of the city from each other. The hilly terrain that characterizes San Francisco was also considered a barrier to walking, biking and running in many cases, despite respondents' appreciation for the views afforded by hills. Like major roadways, large hills can separate sections of the city from each other.
San Francisco’s Pedestrian Barriers depicts three of the main obstacles for pedestrians and cyclists that interviewees mentioned, the inclines of the city’s hills, busy streets and freeways. In addition to showing where difficult crossings may occur, the map is a nice reminder of how neighborhood boundaries may be established. Topography dictates many neighborhood boundaries, many of the rest are defined by large streets cutting across the city. Looking at a plain street map, we may divorce ourselves from the fact that neighborhoods like Russian Hill, Bernal Heights and Noe Valley do have geographic features like hills and valleys associated with them. Neighborhoods that may appear accessible on the street map may be separated by these barriers that are not highlighted on the street map.