What is the distance (by road) between Land's End to John o' Groats?

Land's End to John o' Groats is the traversal of the whole length of the island of Great Britain between two extremities, in the southwest and northeast. The traditional distance by road is 874 miles (1,407 km) and takes most cyclists 10 to 14 days; the record for running the route is nine days. Off-road walkers typically walk about 1,200 miles (1,900 km) and take two or three months for the expedition. Two much-photographed signposts indicate the traditional distance at each end.

Land's End is the traditionally acknowledged extreme southern point of mainland England. It is in western Cornwall at the end of the Penwith peninsula. The most southerly point is Lizard Point, about 9 miles (14 km) further south.

John o' Groats is the traditionally acknowledged extreme northern point of mainland Scotland, in northeastern Caithness.

The straight-line distance from Land's End to John o' Groats is 603 miles (970 km) as determined from O.S. Grid References, but such a route passes over a series of stretches of water in the Irish Sea. Google Earth reports a distance of 602.70 miles between the two iconic marker points.