Towards routine, city-scale accessibility metrics: Graph theoretic interpretations of pedestrian access using personalized pedestrian network analysis
Fig 2
Alternative technical formulations of 400-meter pedestrian service areas.
(Left panel) A circular buffer, calculated “as the crow flies” from a point of interest, is overlaid on the transportation network without concern for physical barriers. (Center panel) A street-based walkshed that uses a monolithic pedestrian model more realistically models traversal of the street network but overlooks pedestrian-specific infrastructure and navigational concerns. (Right panel) A PPNA-based walkshed reveals areas inaccessible to a stereotyped manual wheelchair user. An area in the Northeast section of this map was considered reachable by the street walkshed approach but not by the PPNA approach due to steep sidewalks between the Northwest “Y” intersection and the starting point.