Compton Vehicle Activated Speed Sign
General assumptions and issues:
- Whole days only are assessed - part days (battery runs out or VAS taken down) are filtered out.
- Average vehicle length units are derived from the total data set for a particular VAS site during period of collection usually two or three weeks.
- The sub count for vehicle types involves a lot of statistical modelling and is a bit uncertain.
- Motorcycles (MC) or smaller vehicle assumed to be under average length LESS one standard deviation.
- HGVs or Buses or larger vehicle etc assumed to be over average length PLUS one standard deviation.
- Average speeds for all vehicles AND for those faster than 30 MPH are given
- Percentage of the total vehicles faster than 30 MPH is given
- Really very low daily figures are for days when the battery ran out or was just replaced - not whole-day counts