THE ISSUE: Is a tunnel under North Oxford the best way to solve traffic problems?

In an ideal world, any scheme which diverts through traffic away from residential areas, either by relocating roads away from the area or by burying the roads underground, must be taken seriously.

At this early strategic stage we should disregard the relative costs of these and any other options and should attempt to objectively consider the implications of each of them.

At the same time we need to be mindful of the social and environmental (including technical) obstacles to be overcome.

Busy roads divide existing communities and they discourage the development of new communities. They are dangerous to cyclists and pedestrians and present a hazard to health through air and noise pollution.

Until limits are put on car use (possibly through the use of incentives) and alternatives to road transport are found, the quantity of motor vehicles using our roads can only increase.

The A40 trunk road is already both an obstruction to free and safe passage of pedestrians and cyclists as well as to motor traffic needing to cross or join it. Diversion of the road will only pass the problem on to somewhere else.

Keeping the road where it is and providing ground level crossing points for vehicles, pedestrians and cyclists will add to the pollution levels induced by stopping and starting traffic.

Segregation of different types of traffic by creating different levels is the ideal solution.

The pedestrian bridge linking north and south Cutteslowe is one such solution but infrequent crossing points, whether by bridges or ground level crossings, are not convenient for pedestrians who have to make large detours to use them.

An extended fly-over road on the route of the A40 would allow for free movement of local traffic including pedestrians and cyclists beneath it, but arguably would still have a detrimental environmental impact. Then there is this idea of a tunnel which would bring similar benefits, but with a much reduced impact on the local environment.

Tunnel-building technology has advanced hugely, with the building of the Channel Tunnel. And tunnel building in London seems to have no limits. Hence the existing railway beneath Wolvercote Roundabout should not present any significant problems.

NO: Hugh Jaeger, chairman of Oxford Bus Users.

Tunnels are very costly and building them emits a lot of carbon. Climate change is now so urgent that no tunnel is justified unless its construction emissions are off-set by the amount that it cuts transport emissions.

Ian Hudspeth, leader of Oxfordshire County Council, proposes giving the A40 either a tunnel under north Oxford or a relief road passing north of Cutteslowe. But like Prime Minister David Cameron’s aim to dual the A40 west of Wolvercote, a tunnel or relief road would attract more traffic and therefore increase fuel imports, emissions and climate change.

A40 congestion, long the worst in Oxfordshire, could get even worse next year. In 2015 Chiltern Railways will open Oxford Parkway station, which will attract hundreds of commuters from West Oxfordshire to Water Eaton.

An A40 tunnel would be at least a mile long, and Mr Cameron would insist it were dual carriageway. It would cost way over £100 million. That’s more than Witney Oxford Transport group’s Witney-Eynsham- Oxford tram-train proposal, which would cut A40 traffic instead of encouraging it.

Cutting A40 congestion would also reduce B4044 traffic and A4095 rat-running. The S1 and S2 buses would be quicker and more reliable, which would help Carterton and Burford. A Witney-Oxford tram-train would complement Mr Hudspeth’s ideas of an Oxford airport – St Giles tramway and a passenger service on the railway through Littlemore to Cowley. And trams have zero emissions: ideal for streets in central Oxford.

New rapid transit routes, like new roads, need time and feasibility studies to compare the options and raise the capital. In the meantime we need interim solutions. Every day hundreds of people avoid the A40 by driving up the A4095 to Hanborough station on the Cotswold Line and taking the train. First Great Western has more than doubled the car park, but this only encourages more cars on the A4095.

Network Rail wants to build a second platform at Hanborough to make the trains more regular. This must go ahead, because only then can Stagecoach time the 233 Burford-Witney-Woodstock bus to meet the trains.

Mr Cameron should also implement his idea as soon as possible to double the Cotswold Line track between Wolvercote and Charlbury to let First Great Western increase train frequency.

Then buses meeting trains at Hanborough, Charlbury and Kingham could be more frequent, cutting A40 traffic even more.

More and better public transport is better value than any A40 tunnel or relief road.