In order to understand how well the model reproduces observed traffic levels, the traffic flows generated by the model following assignment are compared to various real traffic counts conducted around the network.

A set of traffic counts, generally in the areas where the model is more detailed, is used in calibrating TMfS. Having completed the calibration process, the remainder of the counts are used to validate the model.

408 traffic count sites were incorporated into TMfS:07 as part of the calibration process. These traffic counts are all included within the modelled area and cover all of the key roads within Scotland. The majority of counts were undertaken in 2007 and came from the Scottish Road Traffic Database (SRTDb). To view the location of RSIs used in the validation process of TMfS:07, please visit the maps page.