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Debate: Bypasses

The Government has made provision for the building of 100 new bypasses in the UK over the next 10 years to ease congestion 'pinch points' on the network. This week we ask Will building more bypasses cut congestion?


For existing problem areas, we must consider why a bypass is needed. What are the problems it is meant to address? What is the nature of the problems and their cause? A bypass must not be a solution looking for a problem nor the answer to more complex difficulties in the way in which a settlement is working.

There are a number of reasons why a settlement may be congested. It may be the market town to which people come from all directions. The parking policy may be non existent or in conflict with the transport policy.

The routes for alternative modes such as walking and cycling may be dangerous or suffer from breaks in their continuity. Public transport may be sporadic, infrequent, poor and expensive. The congestion may be caused by too many people trying to access cheap town centre parking.

If analysis points to any of the above then other solutions should be applied. These may include park and ride, good cycle and footway networks, public transport services meeting education and work needs, new bus stations, integrated parking policies, key pedestrian links and so on.

But if having done all of this or if the analysis shows that unnecessary through traffic is clogging the streets and thereby creating congestion, noise, poor air quality and community severance then a bypass can be the answer.

If such a scheme removes traffic then the health and environment of those from whom the traffic has been removed will be improved.


longer does the 20th century anti-roads at any price rhetoric have any value. The advent of Local Transport Plans and the New Approach To Appraisal has helped to ensure that where bypasses will be provided this should happen as part of an integrated, balanced package that not only includes the bypass but it will be preceded or complemented by other nonroad investment.

So yes, bypasses can reduce congestion. Indeed the bypass may be the key piece of infrastructure that enables the revitalisation of communities, returns previously clogged streets, environmentally enhanced, back to the public and provides a necessary springboard for regeneration and integrated transport opportunities to be delivered.

No In too many cases, bypasses will not work. They can move rather than solve problems - congestion (and sometimes road casualties) will simply migrate to the next village or town. They can become magnets for unwanted and inappropriate development, especially in-fill between the bypass and the village or town.

This development, along with other generated traffic (new trips, or diverted trips from other roads or modes) can wipe out or at least substantially reduce time savings and the congestion reduction. In such cases, traffic then creeps back into the town centre. Newbury bus operators, for instance, report that after initial relief from the bypass, traffic congestion has grown again to nearly pre-bypass levels, assisted by out of town developments such as the new college of further education (nearly 1,000 car parking places).

Other options can solve the problems better. In many places pressing for bypasses, through traffic is under 10% and the real problem is local car trips.

Nationally, 60% of car journeys are under five miles, so walking and cycling are real alternatives for these trips. Targeting travel generators - employer travel plans and safe routes to school - will tackle a lot of local traffic.

Demand management, especially parking controls and charges, and improvements in public transport (frequency, personal security, information, etc) also need to be assessed against road options. Small scale safety schemes and traffic calming have a far better cost-benefit ratio than many bypasses. Railfreight should be considered where the main problem is long distance lorry traffic.

Hastings and Hereford are good examples of bad bypasses.

In both cases, through traffic is tiny - 6-9%. In Hastings, 28% of peak hour traffic is parents taking children to school. In Hereford, over 30% is singleoccupancy car commuting to six major employers - car sharing will reduce traffic more than any bypass. The Hastings bypass is tied to an out of town business park development, inaccessible for the jobless in Hastings; it will also create traffic pressures on neighbouring communities.

Where the main problem is through traffic, bypasses can be the right answer. For most other situations, they are a blind alley.

The facts

Environmental groups have accused the Government of a u-turn after it originally said road building was an option of 'last resort'.

Under the Government's ten year plan for transport 30 trunk road and 70 local bypasses will be built on the UK road network by 2010.

Twenty one local bypasses were accepted in the Government's 2001 local transport settlement in December.

The British Roads Federation is publishing research on 'Britain's bypass progress' at the end of February.

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