I welcome my hon. Friend's endorsement of the Government's strategy to continue to invest heavily in the motorway network and the plans for the M4, which involve expenditure of about £600 million. It is fair to say that the accident on the M4 to which my hon. Friend referred was caused not by a vehicle crossing over the central reservation, but by a vehicle bouncing back off the central reservation. At the inquest it came out clearly that many people involved in the accident were driving too fast and too close together for the prevailing weather conditions. Earlier this month I announced the introduction of motorway matrix signs on the M4 that can display a fog legend. I hope that that will further reinforce the message to road users during foggy weather that it is indeed foggy, although that should be self-evident to responsible motorists.