They are a vital addition to Oxfordshire's emergency services.

The dedicated team who drive through the night gritting the county's roads know their actions could save lives.

Last week, black ice and frost brought chaos to the roads, causing dozens of crashes.

The worst blackspot was Oxford's Eastern By-pass where a string of collisions and cars skidding out of control, forced police to consider closing the road.

County council lorries had gritted the road, but they were recalled following the spate of smashes.

There were no deaths, but the incident provided a timely reminder to drivers that gritting roads is not a guaranteed way of preventing accidents.

In January 1999, nine drivers died in a nine-day period on the county's roads but that accident statistic has not been repeated.

Highways maintenance staff at the council take accident statistics into account when updating their gritting routes.

Brian Short, Oxfordshire County Council's area engineer, is in charge of gritting for the south of the county.

He is based at the council's highways depot in Milton Road, Drayton, near Abingdon.

The council spends £800,000 a year on its gritting programme, which runs from November until March.

Mr Short said: "We hope our work does save lives, but gritting is not a precise science, so we can never guarantee that roads will be ice-free.

"That is why we need to urge drivers to take extra care on the roads at this time of year.

"This year the frost has been particularly bad."

About 40 per cent of the county's major A roads, and the busiest B roads are gritted, while the surrounding counties grit only about 30 per cent of their roads.