Autonomous vehicles could help cities address their climate goals, if they start planning now

Cities need to lay the groundwork now for the arrival of autonomous vehicles (AVs) to ensure that AVs contribute to rather than detract from their transportation and climate objectives. An ACEEE toolkit highlights fundamental strategies that cities can pursue and gives them a policy roadmap.

As cities grapple with transportation challenges, many have started looking to AVs to improve safety, expand mobility options and improve travel convenience. However, these vehicles fundamentally can change how people choose to travel. Their energy and environmental impacts will depend on who owns them, how many miles they travel, and the modes of transportation they displace.

Without specific policies to shape deployment and ensure net energy and emissions benefits, AVs could aggravate transportation challenges. They could add to already growing congestion in urban centers by undermining transit, inducing additional single occupancy travel and encouraging sprawl.

On the plus side, AVs also can bring transportation and societal benefits. Shared fleets that are available on a dynamic basis have the potential to reduce personal vehicle ownership in cities, expand transit service coverage and connect under-resourced communities. As fewer urban residents feel the need to own cars, cities can repurpose land historically dedicated to personal vehicles to support more efficient forms of transportation such as walking and bicycling, denser development where desired and more affordable housing around transit nodes.

So how do cities make sure they achieve the “heaven” rather than the “hell” scenario? Policymakers will need to keep three critical outcomes in mind.

Promote shared-use low-emissions vehicles

To achieve deep greenhouse gas (GHG) reductions from the transportation sector, cities will need to direct residents towards the shared use of clean vehicles. This includes increasing the number of vehicle occupants per trip and discouraging widespread personal ownership of AVs.

In October, Chicago proposed a downtown surcharge, in addition to a heftier per-ride tax, for solo Uber and Lyft trips to address the congestion impacts caused by ride-hailing vehicles, promote shared rides and generate revenue for mass transit upgrades. Additionally, if AVs are to become a long-term mobility solution and help cities achieve their energy use and emissions goals, they will need to be electric and equitably accessible to all residents. 

Create a robust system of multiple efficient modes

Personal autonomous vehicles cannot be the primary mode of transportation for urban residents if cities are to address their transportation challenges and simultaneously meet energy and GHG targets. Cities will need policies that support a connected urban transportation system with efficient mobility options for all residents. Efforts must include increased public transit ridership through sustained investment in transit service and infrastructure, AVs to fill service gaps and investment in first- and last-mile mobility solutions such as docked and undocked bike-sharing and scooter sharing.

In Maryland, the Montgomery County Department of Transportation recently introduced limited flexible-route, on-demand bus service in two zones during specified hours, to better connect residents to transit and commercial hubs, as well as prepare for the arrival of automated transit service. The Ride On Flex service has no fixed stops or schedules, instead allowing residents to book a ride to any destination within the outlined zones.

Ensure the smart, optimized use of public space

Autonomous vehicles can change city planning and land use. In the best-case scenario, if shared use of AVs becomes widespread, cities will have opportunities to reclaim spaces now dedicated to the personal automobile. For example, they could reduce or eliminate parking-space requirements imposed on developers and expand bike and pedestrian infrastructure.

Mexico City is the largest city in North America to eliminate traditional minimum parking requirements, going so far as to replace those minimums with off-street parking maximums. Additionally, the city imposes fees on buildings constructed with parking beyond 50 percent of the established maximum, thus incentivizing developers to keep off-street parking capacity low. Developers are required to abide by another minimum parking requirement, however — for bicycles.

The arrival of AVs could greatly expand such opportunities to deemphasize auto infrastructure. Furthermore, as these vehicles become more commonplace, cities will need to start incorporating smart infrastructure into their landscapes so connected and automated vehicles can communicate with other vehicles as well as streets, traffic lights and road signs.  

Policies available to cities today can help guide the integration of AVs in urban transportation systems to ensure net energy and GHG benefits. Because AVs bring enormous opportunities as well as significant challenges, their potential impact on GHG emissions and energy consumption is very uncertain.

ACEEE’s new toolkit outlines five policy categories that local decisionmakers can use to shape AV use: requirements for vehicle purchase and use; modified parking requirements and pricing; collection and sharing of transportation data; transportation pricing mechanisms; and transit policies. Such policies will help cities reorient their transportation systems away from the personal automobile and toward more efficient modes. They also will ensure that AVs do not detract from urban environments where public transit, walking and biking thrive, connect seamlessly and provide convenient and affordable mobility to all residents.