Trains between London Waterloo and Exeter run on the South West Main Line as far as Basingstoke.

The line's speed limit is mainly 80–90 mph over its whole length from Basingstoke to Exeter.

Initially this was not a great problem, however as traffic and speeds increased the junction became a bottleneck.

The inner pair of tracks are unelectrified through the junction and continue towards the west to Salisbury and Exeter.

[5][6] The 2006 Network Rail South West Main Line Route Utilisation Strategy recommended building an extended section of double track from Chard Junction to Axminster, and a passing loop at Whimple.

The section from Exeter to Coleford Junction, near Yeoford, is still in use as part of the Tarka Line (a community railway, which continues to Barnstaple).