Motorway speed limit will be cut to 60mph to reduce emissions in badly-polluted areas
Mail Online - The trial project will be implemented on the M6 between junctions 6 and 7 near Birmingham; the M5 between junctions 1 and 2 at Oldbury; the M1 between junctions 33 and 34 and the M602 between junctions 1 to three near Eccles.