Vehicle Weights (Hansard, 25 November 1993)

§ Mr. Pendry
To ask the Secretary of State for Transport what action is being taken by his Department to determine how many roads are capable of supporting a gross vehicle weight of 18 tonnes.

§ Mr. Key
The design of road pavements is related to the amount of wear and tear caused by the different types of vehicle. Current design standards take account of both current and agreed future changes in gross vehicle weight limits. The Department's roads are already capable of supporting a gross vehicle weight of 18 tonnes.

§ Mr. Pendry
To ask the Secretary of State for Transport (1) how many road bridges in the United Kingdom are not capable of supporting a gross vehicle weight of 18 tonnes;
(2) what action is being taken by his Department to determine how many road bridges are capable of supporting a gross vehicle weight of 18 tonnes; and what proportion of these are owned by British Rail;
(3) how many road bridges in the United Kingdom will require strengthening in order to safely take coaches with gross vehicle weight of 18 tonnes; and what proportion of these are owned by British Rail.

§ Mr. Key
In 1988 the Department commenced a programme of assessing its structures on the English trunk road and motorway network in accordance with the bridge assessment code which covers the effects of higher vehicle and axle weights which will be permitted in the United Kingdom from 1999, including those of 18 tonne two-axled vehicles. To date approximately 700 structures have been assessed as being unable to carry the future loading in full. When all assessments have been completed, it is expected that approximately 1,100104W structures will be shown to require strengthening. The strengthening of structures carrying the English trunk road and motorway network is programmed to be completed by the end of 1988. Very few structures carrying the English trunk road and motorway network are owned by British Rail, and none of them is expected to need strengthening.

§ Mr. Pendry
To ask the Secretary of State for Transport what considerations underlie the maintenance of the gross vehicle weight limit for coaches of 17 tonnes; and what consideration has been given to raising it to 18 tonnes.

§ Mr. Key
The main considerations in setting weight limits for all classes of vehicle are road wear and the strength of bridges. The agreement reached in the European Community in 1989 on gross weights for coaches on international journeys was based on the use of an 11.5 tonne rear-drive-axle. We are at present engaged in an exercise to assess and upgrade all the bridges in the United Kingdom to accept this heavier axle load. We therefore have a derogation from the directive to retain our existing axle limit of 10.5 tonnes until 1999.
Increasing the gross weight to 18 tonnes while retaining the existing maximum rear axle load would result in all the additional weight going on the front axle. That weight is effectively limited at present by the availability of suitable tyres for safe operation. Furthermore, such a vehicle would have to depend on perfect load distribution to avoid overloading either axle. We cannot therefore now increase gross weights.

§ Mr. Pendry
To ask the Secretary of State for Transport what plans he has to exclude the weight of safety equipment, including TELMA and double glazing, when calculating the gross vehicle weight for coaches; and if he will make a statement.

§ Mr. Key
Our weight limits are designed to protect the infrastructure and bridges in particular. The weight of a vehicle will be felt on a bridge regardless of whether certain equipment is included in a definition of weight or not. Consequently we cannot exclude the weight of any equipment, safety related or otherwise, from the gross weight of the vehicle.