Sat-navs are sending A30 traffic through a Cornish primary school run

Cornwall councillors say sat-navs are sending A30 traffic through village lanes never built for it. National Highways says it’s reviewing the diversion with Cornwall Council. Here’s both sides.

A two-hour journey took four hours. A van did a U-turn on a slip road, straight into oncoming traffic. These are the kind of accounts now surfacing from drivers caught up in roadworks on the A30 in Cornwall, and two of the county’s own councillors say they warned National Highways this would happen months before the cones went out.

In brief:

• Cornwall councillors say sat-navs are diverting A30 traffic through narrow village lanes at Trewint and Tregadillett, not on the official diversion route
• The disruption relates to the Kennards House to Five Lanes safety scheme, a £9.8m project covering six junctions that began on 5 September and runs for six months
• National Highways has responded directly to the criticism, confirming it’s reviewing the diversion arrangements with Cornwall Council

What Cornwall’s councillors are actually saying, and how National Highways has responded

The specific complaint isn’t about the roadworks existing. It’s about where displaced traffic is actually ending up. Cllr Adam Paynter, deputy leader of Cornwall Council, said sat-navs are directing drivers off the A30 towards Trewint, sending “loads of cars piling off there on to rural back roads”, where they travel half a mile before rejoining the same queue, causing what he described as road rage as drivers try to force back into a line that won’t let them in. He described single-track lanes with high hedgerows where drivers have to reverse once a handful of cars back up and said the same pattern is playing out at Tregadillett, where residents are struggling to leave their homes because of the volume, and where he said it’s “dangerous walking little Johnny to school.”

Cllr Adrian Parsons, who represents Altarnun and Stoke Climsland, was blunter still, posting that “all those who this falls under that couldn’t be bothered to listen or consult with the community over the last 12 months leading up to this work should hold their heads in shame,” and calling the six-month timeframe unacceptable.

Both councillors say this isn’t a surprise that caught anyone off guard. Paynter said he and others warned National Highways before work started that the local roads “simply cannot take the volume of traffic” and that the authority “really didn’t want to listen.” Residents back that account. Ali Packham, who lives locally and had to abandon a horse ride on her usual route because it became too dangerous to continue, said concerns were raised at the public meeting where the scheme was unveiled, with people specifically predicting what would happen on the narrow lanes.

Paynter also raised a separate, more fundamental disagreement: he argues the money would have been better spent on a flyover at Plusha junction, Cornwall’s worst accident blackspot, rather than the current programme of junction alterations across six sites. He said locals would likely have accepted other junctions being closed or reduced if a flyover had resolved the core danger point, calling any junction where cars cross a busy dual carriageway “a recipe for disaster”. National Highways has previously said a flyover was considered too expensive relative to the current scheme, which is instead altering junction layouts, visibility, signage and safety features based on collision data across the affected stretch.

National Highways’ response, when it came, engaged with the substance of the complaint rather than deflecting it. A spokesperson said the authority was “sorry to hear about the frustration and disruption” road users and residents have experienced, and explained the scheme’s basis directly: it’s being delivered to improve safety at six junctions following collision analysis that identified a need for changes to visibility, junction layouts, road markings, signage and safety features, with the long-term aim of reducing both the frequency and severity of collisions on that stretch. On the specific point about traffic management remaining visible even when no work is happening, the spokesperson said it stays in place throughout to protect road users, the workforce, equipment and partially completed works, and to let the scheme progress safely.

Importantly, National Highways didn’t stop at defending the scheme’s existence. On the diversion routes specifically, the spokesperson said the authority recognises the concerns raised about their suitability and the effectiveness of signing, has received feedback from a number of road users about traffic using local routes and the impact on nearby communities, and confirmed the project team is actively reviewing that feedback and working with Cornwall Council and traffic management partners to identify possible improvements. Paynter separately confirmed weekly meetings have now been agreed with National Highways, with Cornwall Council’s highways department feeding in advice, and said “things are changing a bit” as a result.

That gives this story a shape worth being precise about. It isn’t a case of an authority ignoring a problem. It’s a case of a genuinely well-evidenced safety scheme running into a diversion plan that appears not to have accounted for how far drivers will go to avoid a queue, and an authority now course-correcting in response to real-time feedback rather than at the design stage. Both things can be true: the six junctions being altered have a documented, serious collision history, and the diversion routing around them has, on the evidence of this week, been getting local roads wrong.

For residents in Trewint and Tregadillett, the practical concern is safety on roads that were never engineered for through-traffic at this volume, particularly with a school on one of the affected routes. For National Highways, the test now is whether the promised review with Cornwall Council produces a diversion plan that actually holds, given five more months of work remain. For drivers on the A30 itself, the advice is unchanged from before this row broke into the open: allow significant extra time, and be sceptical of what the sat-nav suggests as a shortcut.