The Marazanvose bridge, which is 49.3m (161ft) long and 12.5m (41ft) wide, spans four lanes of the new dual carriageway and two lanes of the old A30, now the B3288.

Rather than widening the existing A5, the scheme involves building a whole new dual carriageway just to the west of the A5 (the old road will in time be stripped of its title ‘A5’, and it will ...