Motorway and highway drainage
The overall responsibility for managing motorways and trunk roads lies with the relevant highways agency. Some roads are managed by private companies, and other 'A' roads and all minor roads are managed by local authorities.
There are three major objectives in road drainage:
- To remove surface water quickly to provide safe roads and minimum nuisance
- To provide effective drainage to maximise the life of the road
- To minimise the impact of run-off on the receiving environment
Road drainage can be broadly classified into two elements: surface and sub-surface. These two elements are not completely separate from one another.
Because it is important that water drains quickly from the road surface, it can be difficult to contain polluted run-off from an incident before it enters a local water body.
The highways agencies have access to a wide knowledge base of the area along the national road network, including the location and operation of pollution control devices. They will also be able to call on additional environmental protection equipment and resources from their own incident support units.
Storage bins containing pollution control materials are located near many motorway slip roads. The Storage bins are kept locked and keys are held by environment agency and highways agency traffic officers. See Section 1.7, Environmental Protection Handbook for further information.
A reduced level of pollution control and response exists for locally maintained road infrastructure, and in most cases local authorities can be contacted to obtain pollution control information.