Quantification of the impacts and benefits of future transportation and land-use scenarios
The methods developed can be applied in other major cities in Québec to support climate change adaptation and health-focused land use planning.
Project details
Context
Transportation systems and land use influence decisions regarding mode of transportation and the flow of traffic. The associated health impacts are impressive: road trauma is the primary cause of death among 15-29 year olds, ambient air pollutants and noise from road transportation have been associated with morbidity and mortality due to cardiorespiratory problems, and ambient air pollutants are responsible for ~3% of the global burden of disease.
Dense residential developments favour active transportation and the development of public transit, reducing both physical inactivity and CO2 emissions. However, methods for estimating the health impacts of different transportation scenarios remain largely undeveloped.
Objective(s)
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Develop hypothetical transportation and land-use scenarios for the Montréal Census Metropolitan Area (CMA) for 2061;
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Estimate the number of trips made according to mode of transportation and the distance (km) travelled by vehicle and by active transportation for the 2061 scenarios at an aggregate spatial scale;
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Estimate NO2 and noise levels for the 2061 scenarios at an aggregate spatial scale;
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Estimate CO2 emissions of municipalities in the Montréal CMA based on scenarios for 2031 and 2061;
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Calculate and compare the health impacts associated with the 2061 scenarios.
Methodology
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Create nine 2061 scenarios involving different population distributions (with or without densification of suburban areas) and uses of modes of transportation. In each of these scenarios, fleets of vehicles with different characteristics are used to estimate air pollutant levels.
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Estimate the following health impacts: road trauma, incidence of childhood asthma, death from cardiovascular disease, incidence of cardiovascular disease, diabetes (physical activity) and breast and colon cancers.
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Calculate the health burdens and benefits for each scenario and compare the scenarios.
Results
The project aimed to compare numbers of trips and distances travelled per mode of transportation, air pollution (including greenhouse gas emissions), and health impacts under different transportation and land-use scenarios. Two 2061 scenarios for Greater Montreal were established:
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1) a Business As Usual scenario
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2) an Optimal scenario with urban densification and a reduction in the share of trips by car (76% to 62% in suburbs; 55% to 34% in urban areas).
Variations of the Optimal scenario were also developed by increasing remote working and electric vehicles. Walking and public transit use and the corresponding distances travelled in 2061 were more than 70% higher for the Optimal scenario than the Business As Usual scenario, while car share and distances were <40% lower. Levels of traffic pollutants (such as nitrogen dioxide) were slightly lower for the Optimal scenario than the Business As Usual scenario but always higher in the urban core. Impacts differed between urban and suburban areas, but overall, the Optimal scenario reduced the impacts of the 2061 Business As Usual scenario by 37% disability adjusted life years (DALY), primarily due to the benefits of transport-related physical activity (Figure 1).
Figure 1 : Disability adjusted life years (DALY) for "Business As Usual" vs. "Optimal" 2061 Scenarios
The percentage of trips made by car and public transit were similar for the 2031 and 2061 Business As Usual scenarios, but the distances travelled by car and CO2 and NO2 emissions increased due to population increase.
Despite several limitations associated with very long-term scenario modeling, the project's results suggest that significant measures to counteract urban sprawl and reduce the modal share of car use are needed to significantly reduce transport impacts, including greenhouse gas emissions.
Benefits for adaptation
Benefits for adaptation
The methods developed and the results obtained by the project have attracted the interest of several partners and will be used in other initiatives (e.g. use of scenario information for modelling by the City of Montreal, use of past baseline data in health impact assessments).
The methods developed can be applied in other major cities in Québec to support climate change adaptation and health-focused land use planning.
Scientific publications
Funding
Institut national de santé publique
Ministère de la Santé et des Services sociaux
Direction régionale de Santé publique
Ministère des Transports, Mobilité durable et Électrification des transports