St Erth Roundabout
| St Erth Roundabout | |||
| Location Map ( geo) | |||
| |||
| Location | |||
| Lelant Saltings | |||
| County | |||
| Cornwall | |||
| Highway Authority | |||
| National Highways | |||
| Junction Type | |||
| Roundabout | |||
| Roads Joined | |||
| A30, A3074, B3301 | |||
| Junctions related to the B3301 | |||
St Erth Roundabout is a large roundabout between the A30, A3074 and B3301 to the west of Hayle. It is the western terminus for the Hayle Bypass, which was built as part of the Polstrong - St Erth Improvement. The junction is complicated by the St Ives branch line running through the middle of it.
Plans were drawn up for the A30 St Erth - Newtown Improvement scheme for a modified Dumbbell at this location, connecting the Hayle Bypass with a new dual carriageway to the west. The plan included a roundabout on the south west of the current junction, connecting the current route with the slip roads on the westbound side. There was then link road to the north west of the current junction meeting the A3074 and the eastbound exit slip, with a link road to a third roundabout with the B3301 and the eastbound entry slip road. The west bound exit sliproad and A3074/B3301 link road would make use of the existing bridges over the rail line, and the new road would fly over the top.
Routes
| Route | To | Notes |
| Penzance, St Erth 1 | ||
| Redruth | ||
| St Ives 4, Carbis Bay 3, Lelant 1, Park and Ride to St Ives | ||
| Hayle 1 1/2, Helston 11 (B3302) |