FOI reference: FOI-2025-3150
You asked
I am writing under the Freedom of Information Act 2000 to request comprehensive information regarding the M6 motorway speed restrictions around Junction 3A and surrounding areas.
Speed restriction justification and evidence base
1. I request complete cost-benefit analysis conducted prior to implementation of variable speed limits on M6 Junctions 2-4 (including 3A), including:
- Traffic flow modelling data
- Air quality impact assessments
- Economic impact calculations
- Safety improvement projections vs. actual outcomes
2. All empirical studies, reports, and evidence used to justify the continued implementation of speed restrictions, including:
- Before/after accident statistics with statistical significance testing
- Measured air quality improvements (if any)
- Traffic flow efficiency measurements
- Economic impact assessments on local businesses and commuters
- All considered Cost Vs Benefit scientific analyses considered: regarding impact on overarching road safety, overall contribution to motorist anxiety and the potential detrimental effects on motorist wellbeing, arising from excessive and/or unfounded use of speed restrictions especially variable and temporary restrictions
3. Internal communications, emails, and meeting minutes between 2018-2024 regarding the decision-making process for M6 Junction 3A speed restrictions.
Road Surface Condition and Tire Wear Impact Assessment
1. Engineering assessments of road surface irregularities, including:
- Surface condition surveys for M6 Birmingham area (Junctions 1-8)
- Maintenance schedules and surface improvement programs
- Assessment of how surface irregularities contribute to increased tire wear
2. Environmental impact assessments regarding tire wear particle emissions from road surface conditions, including:
- Studies on microplastic pollution levels in Birmingham area attributed to motorway traffic
- Air quality monitoring data specifically measuring tire wear particles (PM2.5 and PM10)
- Health impact assessments on local populations
Public Health Monitoring and Response
1. Health surveillance data for areas adjacent to M6 motorway, including:
- Respiratory illness incidence rates 2018-2024
- Cancer incidence data for postcodes within 2km of M6 Junctions 1-8
- Any investigations into correlation between motorway pollution and local health outcomes
2. Air quality monitoring data from stations near M6, specifically:
- PM2.5 and PM10 measurements 2018-2024
- Chemical analysis identifying tire wear particle composition
- Comparison with WHO air quality guidelines
Alternative Measures and Future Planning
Studies or proposals for alternative traffic management that would reduce tire wear pollution, including:
- Road surface improvement programs designed to minimize tire wear
- Assessment of variable speed limit effectiveness vs. alternative measures
- Long-term environmental remediation plans
We said
Thank you for your request.
We do not hold the requested information at the geographic level requested.
We only receive high-level data from Ricardo for emission measures in our Environmental Accounts work, but they carry out work at a more local level, which may be of help for you: Ricardo - Air quality monitoring. You may wish to contact them directly for further assistance.
The Department for Transport produce Road Traffic statistics, so may be able to assist you further with your research. They can be contacted via their FOI Contact Form.
The Department for Environment, Food, and Rural Affairs also produce statistics on air quality and emissions, so they may able to help with your queries. They can be contacted at defra.helpline@defra.gov.uk.
The Department for Energy, Security, and Net Zero could also have some data that may help. They can be contacted at foi.requests@energysecurity.gov.uk.
Our health team have confirmed that in relation to your questions on health surveillance, we do not hold data on incidence rates/diagnoses of cancer and respiratory illness. You may wish to contact NHS England for more information on this topic.