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Center for Advancing Research in Transportation Emissions, Energy, and Health (CARTEEH)

A USDOT University Transportation Center

Introduce Low- or Zero-Emission Zones

Introducing low-emission zones (LEZs) or zero-emission zones (ZEZs) in urban areas is a way to regulate high polluting vehicles in places with traffic congestion, poor air quality, or high population density.1 One way to do this is to ban the most polluting vehicles from some or all roads in the LEZ, requiring cities to establish vehicle standards to determine which vehicles would be allowed to enter the zone. A more extensive approach would be to implement a ZEZ that only allows zero-emitting vehicles (including electric vehicles), pedestrians, and cyclists to use the roads in the zone.2 However, there are some exceptions regarding who is not allowed to pass through LEZs and ZEZs, including low-income or disabled drivers, individuals who live within the zone, public transit, and emergency vehicles.3

Considering this strategy will help achieve the goal of the following objectives

  • Less Contamination
  • Less Emissions
  • Less Traffic Noise
  • Connectivity and Inclusion
  • Healthy Destinations
  • Less Traffic Violence
  • Active Transportation
  • Green Space

Transportation lifecycle phases

This strategy is associated with the following transportation lifecycle phases:

  • Construction
  • End of Life
  • Maintenance
  • Material Selection
  • Operations
  • Policy and Planning
  • Project Development

Who's involved

  • Law enforcement
  • Local governments
  • MPOs
  • Policymakers
  • Transit agencies
Introducing low-emission zones (LEZs) or zero-emission zones (ZEZs) in urban areas is a way to regulate high polluting vehicles in places with traffic congestion, poor air quality, or high population density.1 One way to do this is to ban the most polluting vehicles from some or all roads in the LEZ, requiring cities to establish vehicle standards to determine which vehicles would be allowed to enter the zone. A more extensive approach would be to implement a ZEZ that only allows zero-emitting vehicles (including electric vehicles), pedestrians, and cyclists to use the roads in the zone2 However, there are some exceptions regarding who is not allowed to pass through LEZs and ZEZs, including low-income or disabled drivers, individuals who live within the zone, public transit, and emergency vehicles.3

How it Helps

Limiting the number of vehicles who pass through the LEZ or ZEZ will decrease traffic congestion and vehicle emissions.4 This can have significant health benefits by reducing particulate matter (PM) and other pollutant exposure to individuals near or within the zone. Implementing these zones in specific areas, such as near schools, homeless shelters, or nursing homes, will further protect these vulnerable populations.

Implementing

Location and Design:

To determine where to implement LEZs and ZEZs, city planners and government officials should analyze which areas have high pollution and traffic congestion levels or high numbers of susceptible individuals. Local demographics and car ownership rates should also be examined.1

Provide Transportation Alternatives:

Since LEZs would ban high-polluting vehicles—or nearly all vehicles in the case of ZEZs—travelers should be provided with alternative transportation options. This can include expanding pedestrian and public transit infrastructure to ensure that individuals have access to affordable alternatives.

Enforcement:

LEZs and ZEZs can be enforced through tolls, cameras, and local police officers who can give tickets to individuals who violate the zone.3 Additionally, other vehicles who wish to drive through the zone can be required to pay a fee which, in turn, can raise revenue for the city or community. This revenue can be used to expand transit, bicycle, or pedestrian infrastructure, as well as make any other health-promoting modifications to the area.

Potential Barriers:

To overcome public protest and opposition to LEZs and ZEZs, the city will need a wide range of supporters who understand the environmental and health benefits of these zones. This will require significant collaboration among potential stakeholders, including MPOs, government officials, local businesses, and interest groups. The city should also be transparent and provide information to the public regarding the benefits of LEZs.
Additionally, LEZs could worsen traffic levels and congestion in other areas since vehicles would need to choose alternate routes. There should be plans in place to account for this scenario.

Examples

1) London’s Low Emission Zone

In addition to congestion zones and LEZs, London also has ultra-low emission zones (ULEZs). It’s been found that these zones have significantly improved London’s air quality and has allowed the city to meet the World Health Organization’s recommended limit for fine particulate matter. The zones have also resulted in more individuals choosing active or public forms of transportation.

https://www.ucsusa.org/sites/default/files/2021-06/low-and-zero-emissions-zones.pdf

2) Superblocks in Barcelona

The city of Barcelona developed a ‘Superblock’ urban design concept, and within each superblock contains green streets that are closed to most vehicular traffic. Therefore, walking and biking are the primary forms of transport, and the areas have experienced improved air quality, less noise pollution, and greater rates of physical activity. Although there was some pushback from the community over implementing these designs, the city council has focused on fostering equality, and the community has since welcomed the positive changes that superblocks have brought.

https://www.citiesforum.org/news/superblock-superilla-barcelona-a-city-redefined/

1. C40 Knowledge Hub. (2019). How to design and implement a clean air or low emission zone. https://www.c40knowledgehub.org/s/article/How-to-design-and-implement-a-clean-air-or-low-emission-zone?language=en_US
2. Cui, H., et al. (2021). A Global Overview of Zero-Emission Zones in Cities and Their Development Progress. ICCT. https://theicct.org/publication/a-global-overview-of-zero-emission-zones-in-cities-and-their-development-progress/
3. Reichmuth, D. (2021). Zero Emission Zones: A tool to target benefits of vehicle electrification to communities that need it most. The Greenlining Institute. https://greenlining.org/blog-category/2021/zero-emissions-zones-vehicle-electrification/
4. Urban Access Regulations in Europe. Low Emission Zones. https://urbanaccessregulations.eu/low-emission-zones-main