Newcastle’s Clean Air Zone

Newcastle Needs To Catch Up: Bristol Sets The Ambition for Cleaner Air

Our cities are on a critical journey towards cleaner air, and Clean Air Zones (CAZs) are a primary vehicle for this transformation. However, not all CAZs are created equal, nor do they achieve the same level of ambition. While Newcastle has made strides, a closer look reveals that Bristol is setting a more ambitious standard, demonstrating what’s possible when a city truly commits to tackling air pollution and reimagining urban mobility. Let’s explore Newcastle’s progress and compare it with Bristol’s more comprehensive approach, particularly through the lens of “traffic evaporation.”

Newcastle’s Clean Air Zone: Progress, But Room to Accelerate

Newcastle’s Clean Air Zone, a joint effort with Gateshead Council, officially started on January 30, 2023.

What is it? Newcastle’s CAZ is a Class C zone. This means its charges are primarily directed at older, more polluting commercial vehicles:

  • Taxis and private hire vehicles
  • Vans and minibuses
  • Buses and coaches
  • Heavy Goods Vehicles (HGVs)

A key distinction, and arguably a limiting factor in its ambition, is that private cars and motorcycles are not charged within Newcastle’s CAZ, even if they don’t meet the latest emission standards. The zone encompasses most of Newcastle city centre and vital bridge crossings (Tyne, Swing, High Level, Redheugh). Daily charges are £12.50 for taxis, vans, and minibuses, and £50 for buses, coaches, and HGVs.

Is it achieving its aims? Initial data indicates some positive movement. Newcastle has observed a 9% fall in nitrogen dioxide () levels between 2023 and 2024. Encouragingly, the number of streets exceeding legal limits has significantly reduced from 48 in 2019 to just two. This demonstrates that the CAZ is indeed having a beneficial effect on reducing certain harmful emissions.

Where is it not making as much progress, and what are the reasons? Despite these improvements, significant challenges highlight where Newcastle needs to accelerate its efforts:

  • Persistent Hotspots: Two locations stubbornly remain above legal limits: Stephenson Road (near the Corner House junction) and Percy Street in the city centre. Stephenson Road, in particular, is a major concern, with readings substantially exceeding the legal maximum. This indicates that the current measures aren’t sufficient for all areas.
  • Particulate Matter: Progress on reducing other harmful pollutants, such as particulate matter, has been “slower than expected.” This suggests a less holistic approach to air quality improvement.
  • Reasons for Slower Progress: Underlying issues include funding challenges and a concerning “lack of political buy-in” for broader, more impactful measures to reduce air pollution across communities. A stark government prediction estimates that Newcastle could be the last city in England to become compliant with regulations, potentially as late as 2045, largely due to the persistent Stephenson Road issue. While the council has pledged to prioritize action at this junction, the long-term projection underscores a need for greater ambition.

Bristol’s Clean Air Zone: Setting the Ambition

Bristol’s Clean Air Zone became operational slightly earlier, on November 28, 2022. Its design immediately showcases a higher level of ambition.

What is it? Bristol operates a Class D CAZ. This is a crucial difference from Newcastle, as it means all vehicle types that do not meet emission standards are charged to enter the zone, including:

  • Private cars
  • Vans, minibuses, taxis, private hire vehicles
  • Buses, coaches, and HGVs Motorcycles are generally exempt. The zone covers the city centre and harbourside. Daily charges are £9 for private cars, taxis, vans, and light goods vehicles, and £100 for heavy goods vehicles, buses, and coaches. By including private cars, Bristol directly addresses a much larger segment of the polluting vehicle fleet.

Is it achieving its aims? Bristol’s CAZ has yielded impressive results, demonstrating the effectiveness of its more comprehensive approach. Air quality across Bristol is reported to be 10% cleaner a year after its introduction, with levels almost 13% lower inside the CAZ. The city is on track to reach compliance at all monitoring locations by 2025, and a remarkable 88% of journeys into the zone are now made in compliant vehicles. This rapid improvement highlights the impact of a broader charging scheme.

Where is it not making as much progress, and what are the reasons? Even with its ambitious approach, Bristol faces challenges, though often different in nature:

  • Zone Boundaries: Some residents express confusion regarding the zone’s boundaries, particularly why certain inner-city residential areas are excluded while parts of the Portway are included.
  • Traffic Displacement: Concerns persist about traffic being displaced to routes immediately outside the CAZ as drivers try to avoid charges. This is a common challenge for any CAZ and requires ongoing monitoring and mitigation.
  • Public Transport Quality: A significant obstacle to further modal shift is the perceived inadequacy of public transport services, including issues with overcrowding and pricing. While Bristol has invested in improvements, a truly world-class public transport system is essential to fully support the CAZ’s aims.
  • Exemptions and Support: Some residents feel there aren’t enough exemptions or sufficient support for vulnerable groups (e.g., Blue Badge holders) or families who need larger vehicles and cannot afford to upgrade. This points to the social equity considerations that must accompany ambitious environmental policies.

Financial Impact and Investment: A Tale of Two Cities

The financial aspects of CAZs reveal differing strategies and outcomes, further highlighting Bristol’s more proactive stance.

Newcastle’s Financials:

  • Revenue Generated: As of December 2024, Newcastle’s CAZ has generated nearly £7 million from tolls and penalty charges. This revenue is intended to cover running costs, with any surplus directed to other local transport schemes.
  • Grant Funding for Upgrades: The government provided £15 million for a grant scheme to help businesses and drivers upgrade their vehicles, including buses. However, a significant concern is that over £10 million of this funding remains unspent. Only £4.7 million has been paid out, indicating a slower uptake of these crucial grants. This unspent money represents a missed opportunity to accelerate fleet modernization and air quality improvements.
  • Bus Upgrades: While Newcastle offers financial support for bus operators to upgrade their non-compliant vehicles through these grants, the slow uptake of these funds suggests that the pace of bus fleet modernization may not be as rapid as desired. The primary mechanism for cleaner buses in Newcastle relies heavily on these grants for vehicle replacement, as grant funding for bus and coach retrofitting is no longer available following a government decision.

Bristol’s Financials:

  • Revenue Generated: Bristol’s Class D CAZ is a substantial revenue generator, bringing in an average of £2.2 million per month from charges and fines. This makes it one of the most financially impactful emission schemes in the UK outside of London.
  • Strategic Reinvestment: Crucially, Bristol is actively and strategically reinvesting this income. Approximately £6.3 million is earmarked for subsidizing bus routes, directly addressing public transport quality and encouraging modal shift. An additional £2.3 million is planned for road and pavement repairs.
  • Grant Funding and Bus Upgrades: Bristol initially allocated almost £15 million and secured a further £11 million in government funding to support vehicle upgrades, including for buses and larger fleets. This robust financial support, coupled with the direct £100/day charge for non-compliant buses, provides a strong incentive for operators to modernize their fleets. Bristol’s commitment extends beyond just vehicle upgrades to improving the overall public transport experience, making it a more attractive alternative for the public and a crucial component in achieving traffic evaporation.

Commuting Habits: A Deeper Dive into Travel Data

Understanding how people travel to work is fundamental to assessing the impact and potential of Clean Air Zones. Both Newcastle and Bristol regularly gather this data through census information and dedicated travel-to-work surveys.

Newcastle’s Commuting Landscape:

  • Historical Reliance on Cars: Older data (2015) highlighted a significant reliance on cars for commuting in Newcastle, with over 42% for single occupancy and an additional 13.9% for car-sharing.
  • Post-Pandemic Trends: More recent data (post-COVID) for the North East region indicates a strong recovery in car travel, reaching around 90% of pre-pandemic levels. Conversely, public transport patronage (bus and Metro) remains lower, with bus passenger numbers approximately 28% below 2019 levels. This trend raises concerns about a “car-based recovery” hindering climate and air quality goals.
  • Rise of Home Working: The 2021 Census revealed a substantial increase in working from home, with over 26% of North East residents doing so – more than triple the figure from a decade prior. While this reduces physical commuting, it also impacts public transport ridership.

Bristol’s Commuting Landscape:

  • Stronger Active Travel Base: Even before its CAZ, Bristol demonstrated a higher propensity for active travel. A 2013 survey showed 15.6% cycling and 17.6% walking to work, higher than national averages.
  • Recent Shifts (Post-CAZ): The 2024 Bristol Travel to Work Survey provides insights into the CAZ’s influence:
    • Car Use: Despite the Class D CAZ, car commuting saw a slight increase to 37.1% (up from 29.1% in 2023), with 31.3% driving alone. This suggests that while the CAZ is effective in reducing emissions from non-compliant vehicles, shifting deeply ingrained car habits remains a complex challenge.
    • Active Travel: Active travel (walking and cycling) remains significant at 32.3% but saw a slight decrease from 35.8% in 2023. Bristol still boasts a higher proportion of commuters walking or cycling than any other local authority in England and Wales.
    • Public Transport: Public transport use for commuting increased slightly to 24.5% (up 1% from 2023). Within this, train use saw an increase (8.9% from 7.1%), while bus use slightly dipped (15.6% from 16.4%).
    • Hybrid Working: The survey also highlights the prevalence of hybrid working, with 66% of respondents working from home at least one day a week.

Traffic Evaporation: Why Bristol’s Approach is More Potent

The concept of traffic evaporation is fundamental to understanding why Bristol’s more ambitious CAZ design holds greater potential for transforming urban mobility. As the Canvas outlines:

“Traffic evaporation is real — and it’s transforming how we think about mobility in our cities. When road space is reallocated to more sustainable modes like walking, cycling, and public transport, something surprising happens: car traffic doesn’t just relocate — it disappears. This phenomenon, known as traffic evaporation, occurs because people adapt. Some switch to transit, some choose to cycle or walk, others combine trips, change their travel times, or simply decide not to drive at all. This insight challenges the old assumption that reducing road space will inevitably lead to congestion. Instead, it opens the door to reimagining urban streets as healthier, safer, and more efficient spaces — with fewer cars and more room for people. It’s not about forcing change, but enabling better choices.”

Both Newcastle and Bristol’s CAZs aim to encourage a shift away from polluting vehicles, thereby leveraging traffic evaporation. However:

  • Bristol’s Class D CAZ, by directly charging private cars, creates a much stronger incentive for the general public to change their travel habits. This direct financial lever, combined with significant investment in active travel (like improved bike infrastructure and cycle training) and public transport initiatives, actively provides the “better choices” that facilitate traffic evaporation on a larger scale. People are more likely to switch to walking, cycling, or public transport when driving incurs a direct cost and viable alternatives are available.
  • Newcastle’s Class C CAZ, while effective for commercial fleets, does not apply direct charges to private cars. This means the “evaporation” effect on general private vehicle traffic within the zone might be less pronounced. It relies more on indirect behavioral changes and the gradual improvement of the overall vehicle fleet through commercial upgrades. Without the direct incentive for private car owners to change their mode of transport, the city might miss out on the full benefits of traffic evaporation for personal journeys. The persistence of car-based commuting and slower public transport recovery in the North East region (including Newcastle) suggests that without a direct incentive for private car users, achieving significant modal shift for commuting might be a longer and more challenging process.

The challenges both cities face (e.g., public transport quality, perceived lack of suitable alternatives) can hinder the full realization of traffic evaporation. If people don’t have viable, attractive, and convenient alternatives, they may seek to circumvent the zone or simply bear the cost, rather than fundamentally changing their mode of transport. Bristol’s commitment to providing these alternatives alongside its charging scheme positions it as a leader in enabling true behavioral shift.

The Stark Reality: Health Costs of a Twenty Year Delay

The decision to implement a Class C CAZ in Newcastle, which exempts private cars, compared to Bristol’s Class D, carries significant and quantifiable health and associated economic costs. This choice directly impacts the well-being of Newcastle’s residents for a prolonged period.

General Air Pollution Health Impacts (UK-wide Context):

It’s crucial to reiterate the severe and widespread health impacts of air pollution across the UK, which serve as the backdrop for both cities’ challenges:

  • Premature Deaths: Air pollution is the largest environmental risk to public health in the UK, linked to 28,000 to 40,000 early deaths each year. The Royal College of Physicians (RCP) estimates that toxic air could contribute to the equivalent of 30,000 deaths in the UK in 2025 alone.
  • Chronic Illnesses: Long-term exposure contributes to a wide range of serious conditions, including:
    • Cardiovascular diseases (heart disease, stroke)
    • Respiratory diseases (asthma, COPD, lung cancer, reduced lung function)
    • Emerging links to dementia, cognitive decline, and adverse birth outcomes.
  • Economic Burden: The health costs associated with air pollution are immense, estimated at £20 billion per year nationally, potentially rising to £27-£50 billion annually when broader impacts are considered. This includes healthcare pressures, lost productivity, and reduced quality of life.
  • Health Inequalities: The burden of poor air quality disproportionately affects deprived communities, exacerbating existing health inequalities.

Comparing Health Outcomes: Newcastle vs. Bristol

While comprehensive, directly comparable reports for all health metrics are not always readily available, we can infer significant differences based on the cities’ air quality trajectories:

Newcastle’s Prolonged Health Burden:

  • Estimated Deaths: Newcastle specifically estimates around 360 early deaths each year due to air pollution.
  • Persistent Hotspots: The continued presence of levels above legal limits in areas like Stephenson Road (64.5 µg/m³ in 2024, well above the 40 µg/m³ limit) means residents in these areas are exposed to higher concentrations of pollutants for a longer period. This directly translates to prolonged health risks for those living, working, or regularly travelling through these areas.
  • Slower Compliance: The government’s prediction that Newcastle might be the last city to achieve compliance (potentially as late as 2045) implies a much longer timeframe during which its population will continue to suffer the health consequences of elevated pollution levels. This twenty-year delay (from Bristol’s 2025 compliance target to Newcastle’s potential 2045 compliance) means more cases of respiratory and cardiovascular diseases, more hospital admissions, and a greater number of premature deaths compared to a scenario with faster compliance.
  • Economic Cost of Delay: A 2021 analysis for Newcastle estimated that even a 5 µg/m³ reduction in could prevent up to 20 deaths and save almost 60 days spent in hospitals annually, with an economic boost. The delay in achieving full compliance means these potential health and economic benefits are deferred, adding to the burden on local healthcare and the economy.
  • Respiratory Conditions: While specific comparative prevalence data for respiratory diseases in Newcastle vs. Bristol isn’t readily available, the general UK context indicates that air pollution is a major driver of such conditions. The fact that Newcastle continues to have significant hotspots suggests an ongoing and preventable burden.

Bristol’s Accelerated Health Benefits:

  • Estimated Deaths: In 2011, it was estimated that between 200 to 260 deaths in Bristol were attributable to PM2.5 and NO2. More recently, it’s stated that five people die prematurely each week in Bristol due to poor air quality.
  • Faster Improvement: Bristol’s Class D CAZ has led to a 10% cleaner air quality overall and a 13.2% fall in levels inside the CAZ in 2023 compared to 2022. The city is on track for compliance by 2025. This rapid improvement directly translates to a quicker reduction in health risks for its population compared to Newcastle’s slower trajectory.
  • Life Expectancy Impact: A 2011 study for Bristol estimated that the average life expectancy of a child born in Bristol could improve by 2 to 3 months if air pollution concentrations improved as projected from 2011 to 2030. The faster actual improvements due to the CAZ would likely mitigate these projected losses more effectively, allowing residents to live longer, healthier lives.
  • Reduced Hospital Admissions: Research shows that higher air pollution days are linked to increased hospital admissions for conditions like cardiac arrests, strokes, and asthma attacks. Bristol’s efforts to reduce pollution should, in turn, lead to a reduction in these acute health events, easing pressure on its healthcare system.
  • Addressing Pre-existing Challenges: Bristol has a higher rate of death from respiratory illnesses than the England average (110 deaths per 100,000 people in Bristol vs. 94 for England in 2021). More than half of premature respiratory mortality in Bristol is due to COPD, with nearly 10,000 residents on GP registers for the condition. The CAZ is a key tool in actively addressing this pre-existing health challenge.

Conclusion on Health Outcomes:

While both cities face significant health burdens from air pollution, Bristol’s more aggressive and comprehensive approach with a Class D CAZ appears to be yielding faster and more widespread improvements in air quality. This, in turn, implies a more rapid reduction in associated health costs and premature deaths for Bristol’s population compared to Newcastle.

Newcastle’s slower pace towards full compliance, particularly in persistent hotspots, means its residents will continue to experience the adverse health impacts of air pollution for a considerably longer timeframe, leading to a continued burden on public health and the local economy. The data strongly suggests that the political decision not to move to a Class D CAZ in Newcastle has tangible and severe health consequences for its citizens, prolonging their exposure to harmful pollutants and the associated human and financial costs.

Comparison Summary: Bristol Sets the Pace

Feature Newcastle CAZ Bristol CAZ
Start Date January 30, 2023 November 28, 2022
CAZ Class Class C Class D
Vehicles Charged Taxis, vans, buses, coaches, HGVs (private cars exempt) All non-compliant vehicles, including private cars
Progress () 9% fall (2023-2024), 2 hotspots remaining. Projected compliance potentially 2045 for worst spot. 10% cleaner air, 13% lower in zone. Projected compliance by 2025.
Key Challenges Persistent hotspots (Stephenson Rd), slow progress on particulate matter, “political buy-in” issues. Zone boundary confusion, traffic displacement, public transport quality, support/exemption concerns.
Traffic Evaporation Potential Indirect, mainly through commercial fleet upgrades and general encouragement for cleaner travel. More direct, as it charges private cars and heavily invests in active travel/public transport alternatives.
CAZ Revenue (Approx.) £7M (up to Dec 2024) £2.2M/month (as of Aug 2024)
Grant Funding for Upgrades £15M allocated, >£10M unspent £15M initial, +£11M secured
Bus Upgrade Approach Grants for vehicle upgrades (slow uptake); replacement only, no retrofit funding Direct charges (£100/day) + grants + significant investment in bus route subsidies
Commuting Trends Strong car recovery post-COVID, lower public transport use, increased home working. Car use slightly up post-CAZ, strong active travel base, public transport use increasing but bus slightly down, significant hybrid working.
Health Outcomes Estimated 360 early deaths/year. Prolonged exposure due to slow compliance (potentially 2045). Deferred health & economic benefits. Estimated 5 premature deaths/week. Faster air quality improvement (compliance by 2025). Quicker reduction in health risks & hospital admissions.

While Newcastle is making progress, Bristol’s Class D Clean Air Zone, with its broader application of charges and significant investment in sustainable transport alternatives, demonstrates a more ambitious and potentially more effective strategy for achieving rapid and widespread air quality improvements. For Newcastle to truly catch up, a re-evaluation of its approach to private vehicles and a stronger commitment to enabling sustainable choices will be key.

Get Involved: Making a Difference for Cleaner Air in Newcastle

Improving air quality is a collective effort, and there are many ways for individuals, communities, and organizations in Newcastle to get involved and contribute to a healthier environment. Here are some active campaigns and initiatives you can support:

  • Breathe Clean Air (Newcastle and Gateshead Councils)
    • What they do: This is the official source for information on the Newcastle and Gateshead Clean Air Zone. They provide details on vehicle checks, how to pay charges, and financial support for upgrading vehicles.
    • How to get involved: Stay informed about the CAZ regulations and support its aims by ensuring your vehicle is compliant or by utilizing available grants if eligible.
  • Climate Action Newcastle (CAN)
    • What they do: A leading local environmental group campaigning for cleaner air through various initiatives and public engagement. They advocate for stronger policies and empower individuals to take action.
    • How to get involved:
      • “30 WAYS to Cleaner Air Guide”: Download their guide for practical tips on reducing your personal contribution to air pollution (e.g., reducing emissions from deliveries, addressing wood burner use, tackling engine idling).
      • Support “Ella’s Law”: Advocate for the Clean Air (Human Rights) Bill by contacting your MP and supporting related petitions (more info at ellaslaw.uk).
      • Participate in Events: Join their “Welcome Walks,” “Bike Rides,” and other community events to raise awareness and show support for clean air initiatives.
  • Go Zero (Newcastle City Council)
    • What they do: This council-led campaign promotes sustainable transport options to reduce air pollution and carbon emissions across the city.
    • How to get involved: Explore and utilize greener transport alternatives such as Park & Ride services, electric vehicle charging points, and car clubs.
  • Integrated Care for Cleaner Air Initiative (Newcastle Hospitals NHS Foundation Trust & Global Action Plan)
    • What they do: This partnership focuses on improving air quality around healthcare facilities in the North East and North Cumbria, recognizing the direct link between environmental health and patient well-being. They promote sustainable practices within the NHS and advocate for broader clean air policies.
    • How to get involved: Support initiatives like the “No Idling Statement” by turning off your engine when stationary, particularly around hospitals and health centers. Encourage healthcare institutions to adopt sustainable practices.
  • National Clean Air Day (Organized by Global Action Plan)
    • What they do: This annual national campaign (typically in June) mobilizes individuals, communities, businesses, and governments to take action on air pollution.
    • How to get involved: Participate in local events, spread awareness about air pollution’s impacts, and adopt personal habits that reduce emissions (e.g., choosing active travel, conserving energy). Look out for their annual themes and calls to action.

By engaging with these active campaigns, you can contribute to accelerating the pace of air quality improvement in Newcastle and help ensure a healthier future for all residents.

Data Sources

The information presented in this briefing is drawn from a variety of publicly available sources, including:

  • Official Government and Council Reports:
    • Breathe Clean Air (Newcastle and Gateshead Councils) – Vehicle upgrade grants, eligibility criteria, news updates, air quality monitoring data.
    • Gateshead Council – Clean Air Zone application information, news releases.
    • GOV.UK – Clean air zones guidance, vehicle checker, air quality data.
    • Bristol City Council – Key facts, JSNA (Joint Strategic Needs Assessment) reports on air pollution and respiratory disease.
    • North Tyneside Council – Air Quality Strategy, air quality feasibility study.
    • Office for National Statistics (ONS) – Census data on travel to work, life expectancy statistics.
  • Academic and Research Institutions:
    • Energy Saving Trust – Clean Vehicle Retrofit Accreditation Scheme (CVRAS).
    • Imperial College London (Environmental Research Group) – Bristol City Health and Economic Impact Assessment Study, research on air quality health and economic costs.
    • King’s College London – Research on air pollution and hospital admissions, life expectancy impacts.
    • University of Bristol – Modal Share for sustainable transport report, travel surveys.
    • University of Newcastle – Colleague Travel Survey (in partnership with NECA).
    • University of Sunderland Students’ Union – Response to NECA transport consultation.
  • Industry and Advocacy Groups:
    • Asian Standard Newspaper – CAZ grant rule changes, unspent funding.
    • ASLEF (Associated Society of Locomotive Engineers and Firemen) – Consultation response to North East Local Transport Plan.
    • Bdaily – North East mayor launches transport consultation.
    • Blackcircles.com – Newcastle & Gateshead Clean Air Zone Guide.
    • BVRLA (British Vehicle Rental and Leasing Association) – Clean Air Zones information.
    • Caura – Newcastle Clean Air Zone information.
    • CIVITAS – Newcastle upon Tyne modal split data (older).
    • Clean Air Fund – CBI Economics report on “Breathing life into Newcastle”.
    • Global Action Plan – Report on air quality around hospitals in the North East.
    • Lichfields UK – Blog on Newcastle CAZ.
    • LGiU (Local Government Information Unit) – Blog on North East Combined Authority Local Growth Plan.
    • Logistics UK – Clean Air Zones and air quality schemes member briefing.
    • Motability Scheme – Clean Air Zones information.
    • Motorway – Newcastle Clean Air Zone guide, grants, and scrappage schemes.
    • Newcastle Great Park – North East Travel Survey.
    • Newcastle Hospitals NHS Foundation Trust – News on air quality initiatives.
    • Newcastle Transport – Customer survey information.
    • Nomis – Official Census and Labour Market Statistics.
    • North East Combined Authority (NECA) – Local Transport Plan consultation documents, delivery plan.
    • RAC Drive – Newcastle and Gateshead Clean Air Zone information, guide to Clean Air and Low Emission Zones.
    • Royal College of Physicians (RCP) – Reports on air pollution health impacts and costs.
    • routeone – Newcastle CAZ grant funding scheme review.
    • SENRUG – North East Local Transport Plan Consultation response.
    • Shire Leasing – Newcastle & Gateshead Clean Air Zone financial assistance scheme.
    • SPACE for Gosforth, SPACE for Heaton – Campaign group analysis and commentary on Newcastle air quality.
    • State of Global Air – Impact of Air Pollution on Life Expectancy.
    • The Alan Turing Institute – Data Study Group Network Final Report: Bristol City Council.
    • The Developer – Article on air pollution and health.
    • The Transport Network – Article on air pollution and hospital admissions.
    • Thorax (BMJ Group) – Research on incidence and prevalence of respiratory diseases.
    • Traffic Penalty Tribunal – Newcastle and Gateshead Clean Air Zone PCN and Appeals Process.
    • TravelWest.info – Bristol Travel to Work Survey results, surveys, awards & challenges.
    • UK Parliament Committees – Transport North East (TNE) written evidence.
    • UK100 – Bristol City Health and Economic Impact Assessment study.
    • UKRI – Cleaning up our air and cutting the costs of pollution.

This list is not exhaustive but represents the primary sources used to compile the information and statistics presented in this briefing.