IT is as predictable as night following day. Whenever there is a crash on the M3 near Winchester traffic floods into the city to try to beat the congestion.

The narrow streets of Winchester city centre regularly get snarled up as desperate drivers try to avoid the motorway queues.

It greatly adds to the harmful pollution that has forced the city council to declare central Winchester an air quality management area.

Now the Highways Agency is considering introducing a measure to minimise the resulting congestion.

The agency is looking to install a message sign on North Walls in Winchester to guide drivers away from the most congested spots.

A report going to the city council environment scrutiny panel tonight says accidents or incidents between junction nine at Winnall and junction 11 at Compton are occurring two to three times a month. During 2006 there were 29 accidents involving injury.

If there was a crash between junctions 10 and 11 traffic would be unable to access the M3 southbound at junctions nine or ten.

The sign on North Walls would tell motorists to join the M3 at junction 11 near Compton, in theory reducing the volume of traffic at Winnall and Bar End although increasing it through the city centre one-way system.

The Highways Agency scheme would cost an estimated £47,000 to also include a system to revise the traffic lights to take account of the heavier traffic flows.