A390 Probus Bypass: overnight closures start Monday

Anyone who drives the A390 through Probus after dark is about to get used to a diversion sign. Cornwall Council’s contractor Cormac is moving in for a fortnight of overnight closures on the bypass, starting Monday 21 September, to get resurfacing and routine maintenance done while the roads are quietest.

📷Credit: Cornwall Council / Cormac

When the closures happen

The work runs in three phases between Monday 21 September and Thursday 1 October, each closing a different stretch of the A390 overnight.

• 21 to 25 September (Phase 1, resurfacing): a full closure of the A390 at the Roseland junction.
• 28 to 29 September (Phase 2, maintenance): the stretch from Denas Water junction to the A3078 junction towards St Mawes.
• 30 September to 1 October (Phase 3, maintenance): from the A3078 junction towards St Mawes to Trewithen roundabout.

All the closures happen overnight, between 7pm and 6am, with Cormac timing the work to when traffic levels are at their lowest.

📷Credit: Cornwall Council / Cormac

Access to the Roseland stays open

The one reassurance for anyone heading down to the Roseland: access via the A3078 will be maintained throughout. Bus services are also being let through the closure sites, though they’ll be driving slowly to keep the work areas safe. Signage will go up at the main junctions before each closure begins, and drivers are being asked to follow it closely, since the exact access points will shift as the phases progress.

Through traffic that isn’t heading for the Roseland will need to follow the signed diversions at all times while a closure is in place.

What the work actually involves

Beyond the headline resurfacing, Cormac says the programme covers the kind of routine upkeep that keeps a road safe to drive on: minor repairs, flailing, gully emptying, sign cleaning, road sweeping and litter picking.

Reporting a problem or checking for updates

For live information on the closures and diversions, one.network is the place to check, alongside Cormac’s own programming pages for Cornwall (find your local Community Area Partnership under “More detail for local areas”, then “Highways Work Programme”).

Questions about the resurfacing itself go to [email protected], and questions about the wider maintenance activities to [email protected]. Non-urgent issues on a road, highway or footway can be reported to Cornwall Council directly, and anything that looks like a threat to public safety should go straight to the council’s 24-hour line on 0300 1234 222.

The notice was shared locally by the Roseland and Truro Community Area Partnership. Cormac’s own caveat is worth holding onto too: the dates are correct as things stand, but subject to change, especially if the weather turns.