Highways Agency - Safe roads, Reliable journeys, Informed travellers

The Project

The road surface in this area had been showing signs of fatigue and required replacement. Both carriageways were resurfaced with low noise material. The opportunity was also taken to improve drainage from the carriageway and upgrade the road signs, road markings and safety barriers. The bridge decks of Blowinghouse and Gilberts Coombe also had the waterproofing and the expansion joints renewed.

Vegetation works, including the removal of pine trees which had the potential to fall on to the carriageway, and replanting, had been carried out in advance to avoid the bird nesting season.

In order to ensure the safety of both road users and the workforce, much of the work was carried out overnight under a contraflow system. This was supplemented by a tidal contraflow arrangement, accommodating normal and peak commuter traffic flows, during the day.

The laybys were closed throughout the project. The westbound Avers onslip, Tolvaddon exit slip, eastbound Tolvaddon onslip and Avers exit slip were closed periodically in various phases throughout the works.

There was a temporary mandatory speed restriction of 50mph for the duration of the contract, and this was enforced with the use of average speed cameras. Traffic was also monitored by a temporary closed circuit television network which was linked to a free 24/7 recovery service.

Cornwall Council have been undertaking major alterations to Chiverton Cross Roundabout nearby.  Full details of this are available on the Cornwall Council website .

Traffic Management

Works began on 14 June and were programmed to finish in October 2010 but owing to inclement weather the project was completed in November.

The work was carried out in the following phases:

Phase 1: (completed)

Two lanes open eastbound and one lane open westbound during the morning peak flow, and all four lanes open for the afternoon peak flow.  This reduced to single lane in each direction overnight during certain operations.

Phase 2: (completed)

Contraflow on the eastbound carriageway with one lane in use on the westbound carriageway to maintain the three lanes required.  Overnight this became a full contraflow on the eastbound carriageway. During this phase, verge and nearside lane works were undertaken during the day, and other carriageway works completed overnight.

During this phase the westbound on-slip at Avers intersection and the westbound off-slip at Tolvaddon junction were closed for the first three and a half weeks. 

Traffic wishing to access the A30 to travel west from Avers intersection diverted east on the A30 to the Chiverton roundabout returned westwards along the A30.

Westbound traffic wishing to exit the A30 at Tolvaddon junction diverted on the A30, then off at Treswithian junction returned eastwards to exit at Tolvaddon junction.

This phase was completed prior to the August Bank Holiday weekend, when two lanes of traffic were available in both directions.

Phase 3: (completed)

Following the August break, the third phase was a reversal of phase 2 in order to complete verge and carriageway works on the eastbound carriageway. 

The eastbound entry slip road at Tolvaddon and the eastbound exit slip road at Avers interchange were closed for approximately three weeks.  Traffic wishing to access the A30 to travel east to Tolvaddon was diverted west on the A30 to Treswithian junction where it was directed to return eastwards along the A30.

Eastbound traffic wishing to exit the A30 at Avers intersection was diverted to remain on the A30 to Chiverton roundabout where was directed to return westwards to exit at Avers.

Phase 4: (completed)

This final phase, with single lane closures was required in order to complete the project and remove temporary works. To allow quick introduction of the necessary contraflows, traffic cylinders were left in place on the carriageway opposite to where the works were taking place during the daytime, so traffic would have to 'stay in lane' at all times.  

There was a 3 metre width restriction for the duration of the project. Wide load operators were required to call 01392 312638 in advance of their journey to arrange escort through the works. We suspended all lane restrictions for the August Bank Holiday weekend.

Cyclists were not permitted to ride through this section of the A30 whilst the works were ongoing because narrow lanes in operation made it extremely dangerous to do so. There was a legal order in force prohibiting cycling for the duration of the works and cyclists who ignored this could be liable for prosecution.

Tractor drivers were requested to use alternative routes to avoid causing congestion through the works.