A method of assessing bridge safety which was pioneered in the North-East has been adopted nationally.

Durham and North Yorkshire county councils were among the organisations that developed the system for categorising road bridges over railways, in the wake of the Selby crash last year.

The County Surveyors' Society is issuing the guidance to all roads authorities, to achieve a consistent approach to risk assessment.

"The risk ranking model was jointly developed by Durham and North Yorkshire county councils, Railtrack LNE zone, Railtrack headquarters and the Health and Safety Executive following the Selby rail crash," said Chris Tunstall, Durham's director of environment and technical services.

"It is a useful management tool for both road and rail engineers in prioritising the sites most at risk.

"We have already undertaken safety works, in agreement with Railtrack, at three (County Durham) bridges - Plawsworth Station, Littleburn Industrial Estate and Sedgefield Station - with work planned shortly at a fourth, at Browney Lane.

"Railtrack will also be issuing the draft guidance to their zone engineers for close working with highway engineers."

The council carried out a survey of all rail bridges in the aftermath of the Selby crash, using methods that have formed the guidance.