TPB News

Following study, TPB considers strategies for reducing on-road emissions

Jan 26, 2022
Climate Mitigation Study

The TPB's Climate Change Mitigation Study of 2021 determined the types of GHG on-road transportation emissions reduction strategies that would be needed to achieve the region's emissions reduction goals. 

Climate change is real and is having a noticeable impact on the natural and built environment globally, including warming the atmosphere, ocean, and land. According to recent reports, the past seven years have been the hottest in recorded history and the frequency of severe storms have increased, taking a greater toll on infrastructure.

The scale and reach of these recent changes across the climate system are global, so it will require a concerted effort from most countries and urban areas, including by our own region. Metropolitan Washington has adopted a set of climate goals including reducing greenhouse gas (GHG) emissions 50 percent below 2005 levels by 2030 and 80 percent below 2005 levels by 2050.

Vehicles on the region's roads burning fossil fuels are among the major contributors of GHGs. While on-road GHG emissions are forecast to decrease over the next 25 years, the amount and pace of these reductions are significantly below the levels of the regional goals. COVID-19 related restrictions on businesses and travel resulted in a large reduction in GHG emissions in 2020, but in 2021, as the economy started to re-open, those emissions have rebounded. A more concerted effort to implement GHG reduction strategies that can provide a sustained reduction in vehicular GHG emissions is needed to help the region attain its climate change goals.

The National Capital Region Transportation Planning Board's (TPB) 12-month Climate Change Mitigation Study of 2021 (CCMS) determined the types of GHG reduction strategies that would be needed to achieve COG’s 2030 and 2050 GHG emissions reduction goals, through strategies focused on the on-road transportation sector alone, such as cars, trucks, and buses. The study analyzed what it would take to 1) reduce on-road GHG emissions 50 percent by 2030, compared to 2005 levels; and 2) reduce on-road GHG emissions by 80 percent by 2050, compared to 2005 levels. COG’s Metropolitan Washington 2030 Climate and Energy Action Plan (CEAP) identifies many high-level strategies and actions that could reduce emissions across all sectors to meet the regional goals. To answer questions that were being asked by the TPB in late 2020 related to climate change, TPB staff commissioned a study to examine in more detail what strategies and actions could be taken solely by the transportation sector to help the region meet the multi-sector regional goals.

The CCMS analyzed three top-down scenarios and ten bottom-up scenarios. Each bottom-up scenario was examined under three different potential levels of improved efficiency in the region’s electric grid, including a zero-emissions grid.  The CCMS study findings were presented to the TPB in December and the final report is now available.

Some of the CCMS scenarios were more effective than others. The most aggressive scenario painted the following picture for 2050:

People no longer buy cars that use gasoline or diesel. The electricity that fuels nearly every vehicle on the road, including buses, is completely generated by renewable energy and not by fossil fuels.

People are driving less. Trains and buses are free of charge and they are fast. A trip that took a full hour in 2021 only takes 42 minutes in 2050. When people do drive, it can be costly. Everyone pays 10 cents a mile every time they use a motor vehicle, and they pay an additional fee when they drive into the regional core.

In this vision of a climate-friendly 2050, people are less dependent on cars in their daily lives. More people live and work close to transit and more people can walk or bike to work or other frequently visited destinations. On average, people work from home two to four days a week.

The above package of changes was one of a limited number of scenarios that successfully achieved the study’s goal of reducing on-road GHG emissions by 80 percent by the year 2050. The findings suggest that bold policies, accompanied by dramatic lifestyle changes for the region’s residents, could produce desired outcomes over the next 30 years.

Although none of the ten scenarios achieved the study’s goal of reducing on-road GHG emissions by 50 percent for 2030, the study underscored the urgency of the moment and it highlighted the tremendous effort that will be needed to stem the tide of climate change.

The CCMS produced emissions forecasts for 60 different packages of possible changes. Ten transportation scenarios were analyzed in combination with three potential levels of improved efficiency in the region’s electric grid, including a zero-emissions grid. All the packages were tested for both 2030 and 2050.
 

EXAMINING LOTS OF SCENARIOS

The study’s ten transportation scenarios explored single and combination pathways to reduce emissions. The strategies that were examined included measures to: 1) improve vehicle technology, such as stepped-up deployment of electric vehicles; 2) reduce driving, measured as Vehicle Miles of Travel (VMT), by increasing the supply of alternatives to solo driving, as well as reducing demand through road and parking pricing; and 3) transportation operations improvements through strategies like better incident management and traffic signal coordination, as well as future deployment of connected/automated vehicles.

For 2050, one to six of the 10 scenarios, depending on assumptions about the electrical grid, successfully achieved the study’s goal of reducing GHGs in the transportation sector by 80 percent by 2050. Of these, the scenarios that were most successful combined a variety of vehicle technology and VMT-reducing measures along with a clean electric grid.

But experts warn that the world must act much sooner than 2050 to stem the tide of climate change with actions taken in all sectors. The study’s most aggressive 2030 scenario achieved a 43 percent GHG emission reduction by 2030. This fell short of the 2030 goal because full deployment of the most effective measures cannot be implemented in such a short amount of time. However, the transportation sector did achieve a reduction that was large enough to meet the levels assumed in COG’s 2030 CEAP. In the CCMS, the estimated reduction in GHG emissions in the transportation sector, combined with reductions from the other sectors assumed in the CEAP, would allow the region, in total, to reduce GHG emissions by 50 percent by 2030.

Even if there is no silver bullet, the urgency of the moment was not lost on TPB members. When the study results were presented at the board’s December meeting, TPB members expressed a desire to move quickly to incorporate the results into the TPB’s planning activities.

“There’s not a single one of us that is going to make it on our own,” said 2021 TPB Chair and District of Columbia Councilmember Charles Allen, “It’s going to take regional thinking and cooperation… and vision, frankly.” 
 

FURTHER INTEGRATING CLIMATE CHANGE STRATEGIES INTO TPB PLANNING

At the TPB meeting on January 19, newly elected Chair Pamela Sebesky presented her thoughts on how climate change mitigation activities could be integrated into the TPB’s long-range transportation plan, Visualize 2045, and other regional planning activities. As described in a memo from the chair and the TPB vice chairs, the inclusion of on-road GHG reduction goals and a set of multi-pathway reduction strategies in both the LRTP and the regional transportation planning process will help guide transportation investment decisions in the coming years. 

For these efforts to be successful, Sebesky emphasized that the collective commitment of TPB members to take action will be critical along with a consensus of member jurisdictions to adopt a set of strategies that are comprehensive and have a diverse set of actions to offer, so that every jurisdiction can take one or more actions. 

To follow up on the CCMS, Sebesky proposed a two-pronged approach:

  • Explicitly adopt GHG reduction goals for the multi-modal on-road transportation sector. These goals would be consistent and commensurate with the region’s multi-sector GHG reduction goals, which were used for the CEAP.
     
  • Explicitly endorse a set of multi-pathway strategies that are anticipated to reduce on-road greenhouse gas emissions and commit to work towards implementing these equitably and as expeditiously as possible. It is important to note that many of the most effective GHG reduction strategies might not traditionally be a part of regional transportation plans.

As a first step, Sebesky asked staff to develop and distribute a questionnaire for TPB member jurisdictions/agencies on the details of the above two elements, for eventual inclusion in Visualize 2045 and the planning process. This survey will be an opportunity for each TPB member jurisdiction/agency to indicate their support for TPB adopting GHG emissions reduction goals for the on-road transportation sector as well as their endorsement of a set of on-road GHG reduction strategies that they would support and implement. 

MORE: Climate Change Mitigation Study of 2021

Contact: Rachel Beyerle
Phone: (202) 962-3237
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