To ask the Secretary of State for Transport when he proposes to begin the experiment, substituting 70 mph speed limit signs for existing signs comprising a black diagonal on a white background; and if he will ensure the experiment is carried out on a major motorway, such as the M25.
The experiment is already under way at a site on the M1. Traffic speeds are now being measured before the erection of 70 mph limit signs. The signs will come into use in the autumn this year. Speeds will then be studied for a further year to see the effect of the change.