Table 3

MDOT National Functional Classification (NFC) code road classes

1 – Rural Interstate (principal arterial)

11 – Urban Interstate (principal arterial)

2 – Rural Other Principal Arterial (non-freeway)

12 – Urban Other Freeway (principal arterial)

5 – Rural Other Freeway (principal arterial)

14 – Urban Other Principal Arterial (non-freeway)

6 – Rural Minor Arterial

16 – Urban Minor Arterial

7 – Rural Major Collector

17 – Urban Collector

8 – Rural Minor Collector

19 – Urban Local

9 – Rural Local

0 or uncoded – not a certified public road

Messina et al. International Journal of Health Geographics 2006 5:42   doi:10.1186/1476-072X-5-42