using data from a diverse sample of commuters working in Cambridge, UK. We evaluate whether GIS can produce routes that adequately
reflect the characteristics of the actual routes taken using a set of commonly assessed metrics, and ascertain the circumstances under
which GIS-derived shortest distance path routes may reflect those actually taken either particularly well or poorly. We identify
circumstances in which modelled routes could be useful proxies for actual journey characteristics, and suggest implications of our findings
for the assessment of environmental exposures.