COP28: US Transportation Emissions Reduction Calculator

By Melvin Wah, Senior Planner; Kate Sargent, Principal + National Practice Leader, Electrification + Oakland Office Leader; and Alex Hanson, AICP, Director of Transportation Planning

This year’s COP28 conference in Dubai will be a milestone as the world takes stock of its progress on the 2015 Paris Agreement. We will soon find out if we are on track to keep global temperature rise to within 1.5C or need to course correct to meet our 2030 goals.

Within the United States, the transportation sector is the largest contributor to anthropogenic greenhouse gas (GHG) emissions. It is no wonder that municipalities are looking to transportation carbon reduction programs as one of the key tenets of their climate agendas. As the world reconvenes for COP28, Sam Schwartz has created a US transportation emissions reduction calculator to help cities, counties and states meet their transportation GHG reduction goals.

Sam Schwartz is a nationwide leader in sustainable transportation and has worked with many cities to accelerate progress towards decarbonization. A clear understanding of current emissions, the potential emissions reductions of different strategies, and the tradeoffs between alternative investments are critical to making informed decisions. This tool demonstrates some of the sustainability analysis we have used to support our clients in reducing transportation emissions.

Beyond examining emissions reductions, our modelling capabilities enable us to collaborate with clients to estimate how decarbonizing strategies impacts the overall allocation of right of way space across different modes, compute the co-benefits associated with reductions in GHG emissions, and assess the overall return on investments for communities and cities. Ultimately, data and modeling are only one part of the toolkit cities must employ to achieve their climate goals, but these tools constitute a foundational decision support system that can enable informed discussion, evaluation, prioritization, and, most importantly, action.

This calculator is a starting point for localities to understand current transportation emissions trajectories, how changes in mode share could impact this trajectory, and key strategies that can propel carbon reduction. We hope that this calculator inspires conversations about what strategies will move the needle most to achieve zero transportation emissions.

For optimal viewing, please open this calculator on your desktop or any Android devices. For iOS devices, please enable cross site tracking in order to view. Alternatively, you can access a version of the calculator here.

How to use this calculator

Step 1: Select an Area

Select your preferred area of analysis at the city, county or state level within the United States from the provided options. Once selected, information on the area’s current mode share will be displayed.

Step 2: Population Growth

Choose a year-over-year population growth assumption that is most reflective of your area. This will help determine the land transport emissions trajectory up to 2050.

Step 3: Private Vehicle Mode Share Target

Delivering a modal transition will be our biggest lever for emissions reduction. Indicate your private vehicle mode share target in 2050 from the provided options. Based on your selection, the calculator will chart a revised emissions trajectory based on the shift from private vehicles to other modes.

Step 4: Key Strategies

We have compiled eight strategies that will be crucial to reduce emissions over the next few decades. Toggle between the different extents of each strategy that best fits your local context, charting a unique pathway to meeting your own carbon reduction goals. Compare how your choice of strategies impact the existing emissions trajectory, and how it matches up with initial mode share shift. You will be able to assess the effectiveness and limitations of individual strategies against the ideal mode share and develop a specific set of initiatives that will meet your stated climate goals.

From the information provided, the calculator generates four different charts that will be useful for this analysis. An existing emissions trajectory based on today’s conditions and a comparison against a revised mode share shift trajectory sets the stage for each location to understand their baseline and the trajectory they should strive towards. Following the selection of strategies, a chart of the combined impact of strategies and a comparison of the individual effectiveness of each strategy allow you to observe where your area is falling short, and what strategy would be most effective for meeting your emission reduction goals.