11th February 2008

We have been looking at the dangers that exist for motorcyclists and pedal cyclists on 'slippery' manhole covers in the carriageway.

Where grip is required the British Standard recommends a texture to be applied to the covers and this is usually done using a pattern in the iron surface. However, in use the skid resistance of many covers deteriorates rapidly as they become polished by the passing traffic. This results in the covers having a poor skid resistance compared to the surrounding highway surface.

For motorcyclists and certain other road users, including pedestrians, the sudden change in grip between the tarmac surface and the worn iron surface of the manhole cover can be the direct cause of injury or death. Covers with an exceptionally good grip do exist but are not widely used due to their high cost.


Bristol has become the first city in Europe to introduce a new kind of manhole cover that helps to reduce skidding for motorcyclists and cyclists. The new design uses an aggregate infill to the top of the manhole cover itself, meaning there is little difference between the grip value of the cover and the road. In other words there is not the great change in slip resistance that is currently experienced when a wheel leaves the tarmac surface to transverse the iron cover. These new Anti-skid covers are being placed on manhole chambers around the new road system in the Broadmead area during its £15M revamp.

This Source was taken from various information sites, including BBC news.

This article was researched and submitted by Hollie Anderson, on work experience with Durey Castings.

There are currently no documents for this product.