Air quality
What is being done to monitor pollution levels and air quality on roads with high traffic flow?
We are using our existing network of air quality monitors, augmented by data provided by neighbouring boroughs where necessary, to understand any changes in pollution levels in recent months in the vicinity of street space schemes. Details of our monitoring network are available at www.hounslow.gov.uk/airquality .
Where we do not have suitable available primary data we will look to commission diffusion modelling – this uses mathematical models to predict likely changes in air quality levels on any given street on the basis of changes in traffic flow etc.
In places where air quality is not currently being monitored, we are happy to explore adding such sites to our network. There are some sites (such as Hogarth roundabout) that are TfL assets and so in this instance, their involvement would be required.
What benefits in terms of reduced pollution, improved air quality for children and the elderly will the low traffic neighbourhoods bring to Chiswick?
Road closures can have an impact on pollution through encouraging drivers to rethink the journeys they make. This can lead to people using different modes, using different routes, travelling at different times or not making a particular journey. This can assist in reducing car trips and therefore pollution. This concept has been observed and documented in academic studies and is referred to as “traffic evaporation”.
An influential piece of research back in 2002 (Disappearing Traffic – The Story so Far. Cairns Atkins and Goodwin, 2002. Proceedings of the Institution of Civil Engineers, Municipal Engineer 151 March 2002 Issue 1 Pages 13 -22,) looking at 70 case studies concluded: “When pedestrianisation schemes or wider pavements or cycle lanes or bus (and other priority vehicle) lanes or road closures are introduced, pre-scheme predictions of what will happen are usually excessively pessimistic. In practice, it is rare that schemes result in a significant deterioration of traffic conditions. Traffic levels can reduce by significant amounts, with the average being that perhaps 11% of the traffic on the treated road or area cannot be found in the area afterwards.”
What is being done about idling vehicles and the pollution they cause?
The council has put in place a traffic management order to be able to enforce against idling, however our ability to do so is complicated by the need to get the DfT to approve necessary signage on a site by site basis.
The council is currently collecting evidence required to justify approval of these signs and residents who have concerns about a particular location should email traffic@hounslow.gov.uk.
