Impact of Phase One report
A report was prepared for Manchester City Council by The Manchester Urban Observatory to show the impact of phase 1 of the Levenshulme Active Neighbourhood scheme on traffic and air quality. The executive summary is presented here. If you would like a pdf copy of the full report, please email us at levyburnageproject@manchester.gov.uk. This report has been prepared by a third party so is not fully accessible.
Executive Summary
This report presents findings from work undertaken by the Manchester Urban Observatory on behalf of Manchester City Council to monitor traffic and air quality to assess the impacts of Phase 1 of the Levenshulme Active Neighbourhood scheme. The goals of the work were to understand the overall air quality and traffic conditions in the area and identify potential impacts of Phase 1 of the scheme in order to inform subsequent interventions in the area and beyond. Data collection took place between August 2020 and October 2021 to capture conditions before and after the installation of modal filters at key junctions across the area. Nine scientific grade traffic cameras and six scientific grade air quality sensors were installed at sites identified as being of interest by the client and community. The sensors were robustly characterised, calibrated and tested prior to installations to ensure the scientific validity of results. The report focuses on three elements of analysis: i) assessment of air quality, ii) pre-and post-intervention comparison to determine impacts of the scheme and, iii) the identification of other notable traffic patterns.
Assessment of air quality
Concentrations of NO, NO2, O3, PM 1, PM 2.5 and PM 10 were measured across 6 sites of key concern in Levenshulme (Delamere Road, Grangethorpe Road, Manor Road, Slade Lane, Broom Lane and Cromwell Grove) between April 2021 and October 2021. Levels for key pollutants NO2 and PM 2.5 were compared to the regional air quality in Manchester and other comparable urban sites across the UK. NO2 is produced primarily by vehicular traffic, while PM 2.5 is derived from a range of sources. Both are responsible for a range of health problems. NO2 values for the Levenshulme sites range from 20 to 25 ug m-3. The NO2 values for Levenshulme are typical of levels found across Manchester and in the upper half of comparable sites in the UK. PM 2.5 values for Levenshulme range from 4 to 6 ug m-3 and are lower than average levels for Manchester (8 ug m-3) when compared against existing AURN sites (Automatic Urban and Rural Network). They are in the lower quartile of comparable urban sites across the UK. Time series comparison of how air quality changes over time in Levenshulme is broadly similar to trends at comparable sites throughout the measurement period.
Air quality monitoring results suggest that Levenshulme is not a particular area of concern relative to other sites in Manchester and comparable sites in the UK. Using the data collected through this project, we conclude that it is unlikely that air quality has been significantly adversely impacted by the Active Neighbourhood scheme.
Intervention analysis
To compare traffic patterns before and after the Phase 1 pilot implementation two time periods were selected that are as similar as possible in terms of lockdown measures, school opening and weather. Analysis of five sites (Errwood Road, Crossley Road, Chapel Street, Rostron Street and Chapel Street Primary) with baseline data suggest that there have been increases in car traffic of 3%, increases in walking of 31%, and increases in cycling of 108%. The share of active transport, i.e. walking and cycling, increases from 22% to 28%, while the share of journeys taken by car decreases from 78% to 72%. Increases in walking and cycling at these sites suggests that the scheme has increased active transport across the area as a whole, as these comparison sites sit outside of the areas that would be expected to directly benefit from reduced traffic. Post intervention data from Delamere Road, which was filtered in the Phase 1 pilot, indicates that for most days, rates of active transport were equivalent to car-based journeys, with around 500 combined active transport journeys per day. Roads at the edge of the scheme appeared to receive marginally more traffic over time, but patterns are consistent with those seen elsewhere in Manchester and the UK over this period.
Other traffic patterns
There are consistent flows of car traffic throughout the day, with levels not dropping below 200 cars per hour between 8am and 8pm on many roads. Roads at the edge of the scheme are characterised by speeding, especially in the early mornings and evenings. The diurnal use patterns for cars, pedestrians and cyclists tends to peak in the afternoon rush hour. Roads with schools experience exceptionally heavy use at drop-off and pick up times, often characterised by larger numbers of pedestrians than cars.
Conclusions and recommendations
Although the results need to be treated with some caution due to the exceptional changing background conditions of rapidly changing Covid-19 lockdowns, it is possible to draw tentative conclusions and recommendations:
- Air quality in Levenshulme is broadly in line with levels across Manchester, suggesting that the Levenshulme Active Neighbourhood has not had significant impacts. NO2 is more concerning than PM in terms of exceeding new WHO recommended levels. As it is produced primarily by motorised traffic there is clearly a case for further traffic reduction schemes
- Traffic levels before and after the implementation of the Phase 1 scheme suggest major increases in walking and cycling on roads that have been filtered as well as roads that are inside the general filtered area. There is evidence that the modal share on treated roads is approaching the 2040 TfGM target for <50% of journeys to be by car. There is evidence that the scheme has achieved its stated goals to increase active transport
- Traffic increases on roads lying at the edge of the scheme are modest and in line with broader regional trends in traffic levels between 2020 and 2021, suggesting that the scheme has not displaced large amounts of traffic onto these roads
- Speeding is an issue, especially on roads running along the edges of the scheme in the early mornings and evenings. Many through roads experience persistently high levels of traffic throughout the day. School streets are under exceptional pressure at key drop off and pick up times
- To fully understand the impacts of interventions it is necessary to have a greater availability of transport and air quality data for different areas over longer time periods. Continued monitoring of schemes would enable a more detailed evaluation of their wider impacts on critical aspects like health, wellbeing, environmental quality and prosperity.