Marlborough's traffic problems - are there simple answers to the complex questions?

Written by Peter Ridal.

Peter Ridal retired in 2011 after 45 years as a chartered civil engineer specialising in highway planning in various parts of the United Kingdom and, for fourteen years, in the Caribbean, Middle East and Malaysia. Among his recent projects were the Stonehenge Tunnel and highway works for the new Stonehenge Visitor Centre.  He lives in Marlborough.

On 10 February 2016, Wiltshire Council's Strategic Planning Committee approved an outline planning application for up to 175 houses and a hotel on land to the west of Salisbury Road. The existing problems of traffic congestion and air quality on the Salisbury Road were downplayed or ignored by Wiltshire’s planning and transport officers.

But representations from Marlborough Town Council and residents left the committee in no doubt about the town's traffic problems. However this and other objections relating to the Area of Outstanding Natural Beauty were overwhelmed by the Council’s perceived responsibility to deliver its housing allocation.

In making its objection, Marlborough Town Council suggested that a relief road south of the town should be provided to deal with the additional traffic. This suggestion was dismissed by the Wiltshire Council transport officer. So, what can be done?

The central area of Marlborough is defined by a rectangle of roads comprising the High Street, London Road, George Lane and Pewsey Road. Roundabouts at the corners of the rectangle combine and control the incoming flows of traffic from the A4, A346 and the A345.

These roundabouts act like turnstiles, releasing traffic into the town at a rate and speed that it can deal with without causing gridlock or excessive danger to pedestrians. Pedestrian crossings also help to break up the flow of traffic allowing the roundabouts to operate as efficiently as possible.

So, queuing on the approaches to the town should be recognised as a function of too much traffic rather than insufficient road capacity.

A traditional ‘predict and provide’ traffic solution would suggest a north-south bypass to the east of the town. Typically such a bypass could follow the line of the disused railway line from the business park to Ogborne Maizey.  This has been explored in the past and rejected because of its cost and the significant environmental impacts.

It has been suggested - as mentioned above - that a relief road linking the A346 Salisbury Road to the A345 Pewsey Road would provide an effective solution to the Salisbury Road problem. However, since most traffic on Salisbury Road is travelling to the north or east the potential relief would be modest.

Any traffic that diverted onto the relief road would now approach the town via Granham Hill so increasing traffic at this location.  This implies more congestion to the west side of town, and with the possibility of rat-running, there could be even more traffic on George Lane and High Street.

So this proposition could cause an overall increase in congestion.  

At present, there is no proposed route for this relief road, so costs and environmental impacts are not known, but environmental impacts and objections are likely to be significant.

There are other ways of tackling congestion. Some will occur naturally. 'Peak-spreading', for example, occurs when drivers choose to travel earlier or later to avoid congestion. This tends to reduce the longest delays, but extends the busy periods.

Also, congestion deters non-essential trips and encourages alternative ways of travelling other than by car.

Eventually, if housing development continues and car use continues to be the primary method of travel, the time may come when congestion in the town becomes unbearable and air quality becomes an even greater threat to public health than it is at present.

Then the only remaining choice would be to restrict the use of cars for short journeys in favour of alternative ways of travelling such as buses, cycling or walking. This allows for the development of a compelling vision for a cleaner, less congested town with trees and wide pavements. But such a vision depends on a fundamental change of travelling habits.

Currently, Marlborough Town Council is preparing a Neighbourhood Plan.  There will be public consultations that allow members of the public to express their ideas, and this is an ideal opportunity for residents to be involved in the future development of the town.