The motorway that connects London to its most distant airport is also the main road to East Anglia, rolling across the hills of Essex and Cambridgeshire.
A gallery of images sent in by visitors to the site of original photos of motorways — including some impressive views of the M4 and M11 under construction.
It crosses cattle grids and untamed moorland, it climbs 1-in-4 hills and plummets through hairpin bends, it runs single-track through woodland and historic villages. It's rugged and beautiful. Is it really the A39?