Measuring accessibility: prescriptions for performance measures of the creative and sustainable city

Urban journalists and researchers seek performance measures on how one city fares versus another in any dimension. An increasingly important performance measure relates to how well cities advance one important dimension of sustainability – decreased mobile source pollutants and decreased travel for vehicles – and how much driving and congestion is occurring. But is congestion really the problem? This paper argues that a superior metric to measure the sustainability of a city's transportation system should centre around accessibility: resident's ease to visit destinations to meet their needs. This paper explores the issues related to the development of accessibility measures for non-motorised modes, namely bicycling and walking. We describe how difficulties in calculating accessibility measures arise primarily from problems with data quality, the zonal structure of transportation planning models, and the adequacy of models and travel networks for walking and cycling. Drawing from a larger research initiative (www.accesstodestinations.org), we present practical strategies for addressing these issues.