Urban Policy Interventions to Reduce Traffic-Related Emissions and Air Pollution: A Systematic Evidence Map
Creators: name: Khreis, Haneen
name: Sanchez, Kristen A.
name: Foster, Margaret
name: Burns, Jacob
name: Nieuwenhuijsen, Mark J.
name: Jaikumar, Rohit
name: Ramani, Tara
name: Zietsman, Josias
Publisher: name: Zenodo
Year: 2022
Subjects: Urban, City, Policy, Intervention, Emissions, Traffic-Related Air Pollution, Exposure, Health, Climate, Co-Benefits

description: <strong>Background </strong>Urban areas are hot spots for human exposure to air pollution, which originates in big part from traffic. As the urban population continues to grow, a greater number of people risk exposure to traffic-related air pollution (TRAP) and its adverse, costly health effects. In many cities, there is a need and scope for improvement in air quality through targeted policy interventions, which continue to grow and include rapidly changing technologies. <strong>Objective </strong>This systematic evidence map (SEM) examines and characterizes peer-reviewed evidence on urban-level policy interventions aimed at reducing traffic emissions and/or TRAP from on-road mobile sources, thus potentially reducing human exposures and adverse health effects and producing various co-benefits. <strong>Methods </strong>This SEM’s methods follow a previously peer reviewed and published protocol with very minor deviations, explicitly outlined in this paper. Articles indexed in Public Affairs Index, TRID, Medline and Embase were searched, limited to English, published between January 1, 2000, and June 1, 2020. Covidence was used to screen articles for inclusion at the title/abstract and full text levels based on previously developed eligibility criteria. Data for included articles was extracted and documented manually into an Excel database. Data visualizations were created in Tableau. <strong>Results </strong>We identified 7528 unique articles from database searches and included 365 unique articles in the final SEM. There were 58 unique policy interventions, and a total of 1,092 unique policy scenarios. The policy interventions fell under 6 overarching policy categories: 1) pricing, 2) land use, 3) infrastructure, 4) behavioral, 5) technology, and 6) management, standards, and services, with the latter being the most studied category. For geographic location, 453 policy scenarios were studied in Europe, followed by 320 in Asia, 206 in North America, 57 in South America, 8 in Africa, and 7 in Australia. Alternative fuel technology was the most frequently studied intervention at 265 times, followed by vehicle emission regulation at 126 times. The least frequently studied interventions were vehicle ownership taxes, greenspace or blue space, and studded tire regulations, which were studied once each. A mere 3% of studies address all elements of the full-chain—traffic emissions, TRAP, exposures, and health. The evidence recorded for each intervention is hosted in an open-access, query-able Excel database available on the CARTEEH Data Hub (https://carteehdata.org/library/dataset/urban-policy-intervention-f08c), and a complementary interactive visualization tool (https://tableau.tamu.edu/t/TTI/views/SEMDataVisualizationV2/SEMVisualizationDashboard?:showAppBanner=false&amp;:display_count=n&amp;:showVizHome=n&amp;:origin=viz_share_link). Using these outputs, we show how users can find more about the effectiveness of the 1,092 included policy scenarios. For example, the full implementation of the most advanced technical measures to reduce emissions in Gdansk and Katowice, Poland, was modeled to reduce NO<sub>2</sub> and PM<sub>10</sub> canyon street increments from 16-53 µg/m<sup>3</sup> to 7-24 µg/m<sup>3</sup>, and from 5-15 µg/m<sup>3</sup> to 0.2-2.4 µg/m<sup>3</sup>, respectively. <strong>Conclusion </strong>This is the first peer-reviewed SEM to compile international evidence on urban-level policy interventions to reduce traffic emissions and/or TRAP in the context of human exposure and health effects, whilst also documenting reported enablers, barriers, and co-benefits. The open-access Excel database and interactive visualization tool can be valuable resources for practitioners, policymakers, and researchers. Future updates to the SEM and its database and visualization tool are recommended. <strong>Protocol Registration</strong> Sanchez, K.A., Foster, M., Nieuwenhuijsen, M.J., May, A.D., Ramani, T., Zietsman, J. and Khreis, H., 2020. Urban policy interventions to reduce traffic emissions and traffic-related air pollution: Protocol for a systematic evidence map. Environment international, 142, p.105826. <strong><em>Keywords: Urban; City; Policy; Intervention; Emissions; Traffic-Related Air Pollution; Exposure; Health; Climate; Co-Benefits</em></strong>
description: This manuscript is complemented by two open-access tools: a query-able Excel database (https://carteehdata.org/library/dataset/urban-policy-intervention-f08c), and an interactive visualization tool (https://tableau.tamu.edu/t/TTI/views/SEMDataVisualizationV2/SEMVisualizationDashboard?:showAppBanner=false&amp;:display_count=n&amp;:showVizHome=n&amp;:origin=viz_share_link). These tools may undergo development to improve their utility. This work was conducted with support from the Texas A&amp;M Transportation Institute's Center for Advancing Research in Transportation Emissions, Energy, and Health, a U.S. Department of Transportation's University Transportation Center, College Station, TX. The grant number is 69A3551747128. More information about the Center for Advancing Research in Transportation Emissions, Energy, and Health is available at https://www.carteeh.org/. Haneen Khreis received funding from the European Research Council (ERC) under the Horizon 2020 research and innovation programme. The grant agreement number is 817754. This material reflects only the authors' views, and the Commission is not liable for any use that may be made of the information contained therein.