Co-Benefits and Trade-Offs of Low-Carbon Policies in the Transportation Sector

Focus Area

Climate Change


Air Quality, Environmental Process






2-3 years

Research Idea Scope

With rising concerns over climate change impacts and the resilience of urban infrastructures, cities are increasingly held accountable for their total carbon footprint and for their ability to identify and prioritize strategies able to achieve deep reductions in greenhouse gas (GHG) emissions. Various metropolitan areas have gone through 80×50 exercises, with the ultimate objective of identifying policies that can reduce GHG emissions by 80% in 2050, compared to a base year. At the heart of initiatives promoting the sustainable growth of metropolitan areas is a strong emphasis on the development of compact, mixed-use urban centers that are able to reduce automobile dependency, while promoting active transportation. There is also a strong push towards the electrification of transport and shared mobility. In response to these driving forces, many cities have witnessed massive changes to their downtown cores. From rising skylines to busy bike lanes, downtowns have experienced the most transformative changes in their infrastructure and social fabric. On the other hand, tall buildings, narrow urban canyons, crowded streets, limited green spaces, and high real estate prices are associated with a number of environmental, social, and heath burdens. While the literature swells with information on the carbon footprint of various land-use configurations and transportation options, there is scant information on the net effect of these policies on the environment (e.g. air pollution, noise), society (e.g. gentrification), and public health. The objective of the proposed research is to investigate the effects of land-use and transportation policies primarily intended to reduce GHG emissions, on environmental quality, road safety, and public health, while capturing social and spatial equity in terms of the distribution of these effects across the population. This information can then be applied to help prioritize policies for implementation.

Urgency and Payoff

The proposed study is very timely as it would complement and inform the recently initiated NCHRP 25-56 study to identify and assess mitigation measures for GHGs. It would provide critical information that would help guide the prioritization of GHG emission reduction measures through consideration of important co-benefits (environmental quality, road safety, public health, etc.) in addition to standard criteria such as costs and emission reductions.

Suggested By

Marianne Hatzopoulou University of Toronto 416-978-0864

[email protected]