The Severn Across 400 has a control at Membury Services (on the M4, ingress/egress via the access road obv.). The next control is the finish in Chalfont St Peter. Free route between controls mean you can follow the official laney route[1] or sneak over to the A4 through Wickham, joining at Newbury, and then blat the ~40 miles along the A4 all the way to Taplow during the night (it's usually midnight when I leave Membury Services).
Going the other way I've done the A4 from Brentford to Maidenhead on my way to a weekend piss up in Witney (Oxon).
The A30 is good too as most of the traffic goes on the A303. I've done ~90 miles of it from Stockbridge to Honiton on my way from London to Cornwall.
Oddly, I love the A4.
The Severn Across 400 has a control at Membury Services (on the M4, ingress/egress via the access road obv.). The next control is the finish in Chalfont St Peter. Free route between controls mean you can follow the official laney route[1] or sneak over to the A4 through Wickham, joining at Newbury, and then blat the ~40 miles along the A4 all the way to Taplow during the night (it's usually midnight when I leave Membury Services).
Going the other way I've done the A4 from Brentford to Maidenhead on my way to a weekend piss up in Witney (Oxon).
The A30 is good too as most of the traffic goes on the A303. I've done ~90 miles of it from Stockbridge to Honiton on my way from London to Cornwall.
I've done most of the A470 too. Cracking road.