Title of Example

Example

Bristol has been monitoring air quality for many years and one of the more difficult aspects is to provide information to the public in a clear and non-technical way, but without being misleading. This has been important in the past because, before assessing air quality became a statutory requirement in the UK, Bristol was one of the few cities in the country which monitored on a regular basis. The media, especially the local papers, assumed that Bristol had an air quality problem greater than any other British city simply because there was local information available. Since the rest of the UK has had to go through the Review and Assessment processes for air quality, it can clearly be demonstrated that the air quality problem is typical for a city of its size.

Before the statutory process Bristol produced annual air quality reports. These had limited circulation and became quite technical documents designed for the more academic reader. The R & A process has resulted in more technical document written for the UK Government which has, to some extent, replaced the annual air quality reports.

A simpler description of local air quality appears in the regular Indicators of Quality of Life report which describes a variety of indicators including environmental ones such as air quality. This document has a wide circulation both to academics, researchers and members of the public. A pdf version of this document can be found at www.bristol-city.gov.uk/qualityoflife.

Internet

The availability of the internet has allowed much more information to become available to more people in the city and beyond. Bristol City Council air quality pages can be seen at www.bristol-city.gov.uk/airquality and included information on what pollutants are monitored, how and where they are monitored. There is also information on the Air Quality Management process and Although it is hoped that real time air quality information will be available on the web site from the continuous analyser network across the city, restriction from the IT department has not made this possible. For this reason graphs are produced each month for the different monitoring sites and these are posted.

Most of Bristol rarely exceeds the hourly limit of 150ppb(286 µg/m3) for nitrogen dioxide and so, using the UK Government’s banding scheme, the air quality is usually in the “LOW” category. However, monitoring and modelling has shown that the annual average of 21ppb (40µg/m3) is exceeded in a large part of the city centre and major roads. For this reason the monthly graphs for NO2 do not have the bandings of Low, Moderate, High and Very High on them, but instead have a line showing the average for that month plus a line for the annual limit. If the monthly average line is above the annual limit line and unhappy face is displayed. If the monthly average line is below the annual average line then a happy face is displayed.

In addition to the sites monitoring NO2, there are also graphs for PM10, temperature and a wind rose showing wind speed and direction for the month.

All of these graphs are automatically generated from and Excel spreadsheet when the latest data are imported from the data collection system.

Consultation

As part of the Review and Assessment process it was necessary to consult the public on the proposal for declaring an Air Quality Management Area (AQMA). At the beginning of the process a leaflet was produced which was delivered to every address in the city. It explained what the City Council was doing in the R & A process and the possible need for and AQMA. When extensive monitoring and modelling had been completed a proposed AQMA was drawn on a map. This was put in a second leaflet and distributed to every address that was within the proposed area.

Variable Message Signs

In 1996 Bristol City Council was involved in a European Project called ELGAR - Environment Led Guidance And Restraint

The overall objective of the ELGAR project was to test a variety of transport strategies to encourage motorists to switch to using public transport, leading to lower, more acceptable levels of environmental pollution.

The project focused on the A4 Bath Road corridor where a variety of transport measures were introduced in three phases:

1. Conscience measure - Variable message signs (VMS) advising drivers when air quality in Bristol is poor. Sited to encourage drivers to use a bus based Park and Ride site.
2. Attraction measures - Systems to improve the attractiveness of public transport including bus priority at key junctions, real time information at bus stops and car journey times on VMS.
3. Restraint measure - A trial of an environmentally sensitive Road User Charging scheme.

The ELGAR project was funded by the European Commission as a part of the CONCERT project. It involved 8 European partners.

The results of the project showed that providing air quality information and public transport promotion can play a role in encouraging modal shift during times of poor air quality. However, the main problem encountered was that the hourly concentrations of the monitored pollutants do not normally exceed the threshold which puts it into the moderate or high bandings so during the life of the project the short-term air quality was rarely bad enough for the signs to be activated and for there to be a change in driver behaviour. There was also a problem with timing. When data were polled from the continuous analysers, the hourly average was calculated at the end of each hour. There would then be a delay before the information was sent to the control system for the Variable Message Signs. If there was going to be an air quality problem in the city centre caused by morning rush hour traffic then the rush hour would be nearly over before the correct information was at the VMS control centre.

Other parts of the project were more conclusive. These included introducing bus priority improved bus journey times in the morning peak period. The ability to compare bus and car journey times was felt by participants to be the best awareness raising measure.

The Road User Charging trial showed that a reduction in daily car trips can be realised by charging for road use when good quality public transport alternatives are available.

Last Updated

13th January 2005