Effects on health of traffic relief options

The potential impacts of the traffic relief options are listed below; they are laid out in Table 1 to help with comparisons.

Although this report addresses some of the likely impacts of transport on health, it is important to note that changes to road configurations and highway regulations may have unpredictable consequences, and new roads may generate unforeseen effects. An example of this is the fact that traffic speeds in Oxford High Street have increased since private cars were banned during the day as part of the Oxford Transport Strategy, reducing traffic volumes and thus allowing buses and taxis to travel faster. Factors such as this add to the uncertainty surrounding the speculations within this report.

HGV weight limit routing

It is very difficult to quantify the impact of an HGV weight limit on air pollution, but it is likely that air quality within the town would improve. It is also very difficult to quantify the impact on traffic injuries. Although a weight limit is likely to improve the situation, reduced HGV flows may lessen the perception of risk by pedestrians and cyclists, thus exposing more of them to traffic danger, especially if speeds increase as a result of lower traffic volumes.

Reduced HGV flows would remove a major disincentive to walking and cycling, and would thus be likely to lead to an increase in levels of physical activity; this would, however, be very difficult to quantify. Reduced HGV flows may improve the urban environment and lead to higher levels of physical activity for town residents, but the emptier roads could encourage car use, thus paradoxically reducing activities such as walking and cycling.

It is likely that an HGV weight limit would reduce community severance, unless lower volumes of traffic were to lead to higher speeds within the town.

Noise levels would probably be considerably reduced if HGVs were removed from the town centre, but alternative traffic patterns with different noise characteristics - such as intermittent noise produced by less frequent but faster vehicles - might arise.

Access would be likely to improve, especially if reduced HGV flows stimulated the retail environment, and health inequalities would probably be reduced if fewer HGVs were to travel through and near the town. If HGV limitations were part of a countywide move to restrict road transport this might have a major and widespread effect of reducing health inequalities.

If HGVs are merely diverted to other roads it is likely that the health of people living near those roads will be adversely affected; this harm could be minimised with careful routing away from areas of housing and recreation.

Woodstock bypass

A bypass is likely to produce lower levels of pollution within Woodstock town, but pollution in the Glyme valley would increase, especially if the bypass were to generate extra traffic. This likely increase in traffic would result in greater production of greenhouse gases.

Traffic danger is very difficult to quantify. It is possible that injury rates would decrease, but they are already at a low level, and lower volumes of traffic might lead to higher speeds and greater traffic danger within Woodstock town. Injury levels on the bypass are impossible to estimate at this stage, but people living near the bypass would be exposed to much higher levels of traffic danger.

The impact of a bypass on levels of physical activity are very difficult to quantify. Although a bypass may lead to higher levels of physical activity for town residents, emptier roads may facilitate car use, thus reducing walking and cycling. A bypass would be likely to reduce walking and cycling activity in the Glyme valley.

It seems likely that a bypass would reduce community severance within the town, but if traffic speeds increase it might stay the same or worsen. There would be a significant worsening of community severance for residents in the vicinity of the bypass.

A reduction in traffic within the town would result in lower overall noise levels, but might generate alternative traffic patterns with different noise characteristics: eg intermittent noise produced by infrequent vehicles at certain times. Bypass traffic would generate noise in an area that currently has low levels of traffic, and there is potential for continuous background traffic noise. The population most affected by noise is likely to change from those in the centre of the town to those on its outskirts.

It is impossible to quantify the effects of a bypass on access and mobility at this stage. Bypass construction may encourage the use and thus development of more distant shopping, employment and leisure facilities, and thus worsen the access problems of those with barriers to mobility such as children, the elderly, or people with disabilities. If, however, the town centre environment were to improve, access and mobility might be enhanced.

Health inequalities are likely to worsen if a bypass is built, with town centre residents seeing improvements at the cost of those on the outskirts; the desirability of properties near a bypass would decrease, thus altering the housing market and further worsening inequalities.

Continuing with the current situation

Certain aspects of the health impacts of the current situation are addressed in the section above entitled 'Effects on health of current levels of traffic on the A44.'

If, however, significant traffic calming and improvements to the environment for pedestrians and cyclists were successfully instituted it is likely that speeds and volumes of traffic would diminish, resulting in a reduction in pollution and traffic danger, lower noise levels, improved access, reduced inequalities, and reduced community severance. A safer and more pleasant urban environment is also likely to increase the levels of activity such as walking and cycling. It seems likely that this would require a more radical solution than the current traffic calming proposals for Old Woodstock; although they are an excellent start, they alone are unlikely to produce an urban renaissance.

The health costs of such a move would be borne by people living near roads which saw an increase in traffic as a result of drivers avoiding Woodstock. There is also the potential for a worsening of air quality if the measures created traffic queues. If such an initiative were to be successful at improving health it would have to reduce traffic, not merely divert it, although significant gains might arise merely from slowing traffic and reducing its impact on the town.