What are the air pollution impacts from the construction and operation of new roads?

Rationale for new or widened roads is often to relieve congestion or to support economic growth. But whilst the predicted environmental impacts of road developments are assessed in the planning stage, there is little appraisal of road schemes once they are built.

A new study has focused on the construction of a dual carriageway in south-east London. Residential air quality was measured before, during and after the completion of the road works. PM10 increased during the construction period during working hours and once opened, the widened road attracted more cars, taxis and light goods vehicles from the surrounding road network. This led to a notable deterioration in residential air quality during rush hours. The widened road also breached the NO2 EU Limit Value. Furthermore, some measures of PM10 toxicity increased after the road was widened, consistent with that related to vehicle tyre, brake and road wear.

The study was funded by Bexley Council and was supported in part by a contract (4719-RFA04-1/04-15) from the Health Effects Institute. Results from the study have been published in open access format in the journal Science of the Total Environment.

Item date 10/09/2014