Derriford Transport Scheme FAQs
What are you doing?
We are creating extra lanes for general traffic, including two new lanes on the outbound side of Tavistock Road (as it approaches Derriford Roundabout), an additional lane on the roundabout itself and an additional lane in each direction on William Prance Road.
Priority measures for buses are being improved, along with routes and crossing points for walkers and cyclists.
We are also replacing ageing traffic lights with new signals incorporating technology that is more efficient and can be more responsive to changing traffic flows through the day.
Why do you need to do this?
This section of the A386 is extremely busy and regularly suffers from congestion, especially during peak times. It will get even busier with planned development and growth in the north of the city.
To support the city’s growth, accommodate the extra traffic that will be generated and help reduce delays we need to improve our transport infrastructure.
We also need to increase travel choice by making alternative options more appealing, which means improving bus service reliability and making it easier and safer for people to walk and cycle in this part of the city.
How much will it cost?
£13.29 million – £10.16 million of which is being provided by the Heart-of-the-South-West Local Enterprise Partnership (HotSW LEP), secured through a Growth Deal with Government. The remaining £3.13 million is being covered by contributions from local developers.
We have contributed an extra £3.45m for essential carriageway reconstruction works to be carried out as part of the scheme works to improve the structural condition of the road which was coming to the end of its life. This will avoid the need to return to the site in a couple of years to carry out reconstruction and the disruption this would cause.
How did you develop the scheme?
We carried out extensive consultation with the public in 2008 to understand how people travelled along the A386 and the issues they faced. We also collated data on existing and forecast journey times, length and duration of traffic queues, vehicle numbers and traffic flow.
After funding options were identified in 2013, traffic modelling and feasibility testing were carried out and four scheme options were presented for public consultation in 2014 – including two types of signalised junction, a flyover at Derriford Roundabout and an upgrade of Derriford Roundabout and the William Prance Road junctions.
Further modelling showed the last two options to be the best performing and while both offered similar benefits, the roundabout and junction upgrade was by far the most cost-effective. This preferred option was presented to the public and awarded funding through our regional funding body (the Heart of the South West Local Enterprise Partnership) in 2015.
Aren’t you just moving the problem? What about the bottleneck further north?
This is just one of a number of infrastructure improvement schemes designed to improve traffic flow along the city’s northern corridor and support planned growth in this area.
We recently consulted on different options for widening Tavistock Road between Woolwell Roundabout and the George Junction and expect to put forward a preferred option in Spring 2018.
Other transport improvement schemes in the area include the proposed brand new route from Forder Valley Road to Brest Road in Derriford (which will create a new link between the east of the city and the north), our recently completed Marjon Link Road and our new two-way bus interchange at Derriford Hospital.
Other transport improvement schemes in the area include the proposed brand new road linking Forder Valley Road and Brest Road in Derriford (which will create an alternative route to the north of the city avoiding Manadon Roundabout), our recently completed Marjon Link Road and our new two-way bus interchange at Derriford Hospital.
Why were the trees removed?
We had to create enough space to widen the road but we made every effort to minimise the number of trees lost by altering the alignment of the road and keeping the more mature trees wherever possible.
As part of our landscaping plans we will be planting new trees, including beech and oak, in the central reserve just south of Derriford Roundabout and on the roundabout itself. We will also be planting wildflowers alongside the walking and cycling paths and on the roundabout and looking at opportunities to plant additional trees in the wider area.
When will the works be finished?
While the construction contract ends in May 2018, the scheme is expected to be substantially complete by the end of March and we have already started to lift traffic restrictions in phases.
This is despite a number of unforeseen setbacks, including the discovery of phosphorous grenades and uncharted abandoned water tanks buried within the construction site.
How did you not know about the grenades?
There is always potential for finding unexploded ordnance in areas that have been subject to aerial bombardment or where military installations have been located historically and this was identified as a risk from the outset. Routine control and mitigation measures were put in place and workers briefed on the procedures to follow if they were to discover any potential hazards.
A radar survey was carried out before work began but the white phosphorous grenades that were uncovered are difficult to find using standard surveying techniques. They were not dropped from the air but buried deep underground and as this sort of grenade was encased in a glass canister (and not metallic) it is more difficult to detect.
Why has there been so much disruption?
Major works like this are disruptive, especially on such a busy route. That’s why we’ve been continually reviewing and adjusting the programme with our contractor to reduce the impact wherever we can.
We have suspended the bus lane restrictions throughout the works to maintain two traffic lanes on Tavistock Road and we have been accelerating and re-programming works, extending the length of the working day and working nights wherever possible to make the best use of available resources and reduce delays.
The contractor has a full-time traffic safety control officer on site who regularly reviews traffic management for the works and our Urban Traffic Control Team monitors the area and adjusts signal timings to improve traffic flow during construction.
Why have you allowed other roadworks in the area at the same time?
Utility companies often have to carry out essential works at short notice but we are able to suggest changes to their timings and traffic management proposals. Wherever appropriate we will ask for works to be carried out at night or during off-peak times.
Where works are not urgent we avoid programming them alongside major road improvements unless their impact is likely to be low or there is a benefit in taking advantage of the traffic management already in place (to avoid future disruption).
Why aren’t contractors working longer hours to get the scheme finished quicker?
There are around 50 workers on site each day and 16 at night. Teams have been working every night since the summer (weather permitting) and two to three nights a week before that. See our nightworking video for more information.
Why are there already potholes on the road?
When works are complete the whole scheme area will have been completely resurfaced. There are some sections where the final wearing course has not yet been laid and the temporary surface is more susceptible to defects in colder or wetter weather. Any potholes in the scheme area can be reported to our contractor at firstname.lastname@example.org.