Health and air quality improvements are the key aims of a CAZ. However, there is potential for a CAZ to bring secondary benefits. If a class D CAZ was introduced, a possible short-term benefit could be a reduction in the number of journeys made by private vehicles, which could reduce traffic levels, improve bus patronage and result in faster and more reliable journey times.
If fewer people are developing health problems than before then this could provide economic savings to the NHS and economic benefits from reduced absenteeism. It is also possible that some measures included as part of a CAZ will create better conditions / infrastructure / facilities for cyclists and pedestrians in Bristol, leading to public health benefits arising from increased active travel.
A Clean Air Zone could also improve the attractiveness of Bristol in the long term, as a healthier place to live, work and visit.