​NCC cannot grit all of Norfolk's 6,159 mile (9,911 km) road network because of the time it would take and the cost involved. Priorities for gritting roads have been established on the basis of the route hierarchy and level of use.  The main roads will be gritted before other routes. Our three hour gritting runs cover a total of approximately 2,200 miles (3,500 km) on A, B and some C class roads - commuter and major bus routes and as far as is possible one route into all villages.  Some footways in the pedestrian areas of central King's Lynn, central Great Yarmouth and central Norwich are also treated as priority. National Highways treats 143 miles of trunk roads including the A11 and A47. While it is unlikely that any additional roads will be added to our current schedules, if you feel you have an exceptional case for amending them, you should contact your Parish or Town Clerk. If you live in Norwich you should contact your local councillor. Although the County Council carries out the assessment in line with the Winter Service Policy, the view of a parish or town council is important and is taken into consideration. Due to limited salt capacity on the gritting vehicles and time constraints, it is likely that an existing road may need to be removed from the current schedule to accommodate a new addition.​