How Will Autonomous Driving Impact Boston's Transportation Emissions?
The next frontier in transportation is autonomous vehicles (AVs) and in this arena, Boston is on the cutting edge. Two companies, Optimus Ride and nuTonomy (Aptiv), are already test driving AVs on Boston's public streets. While AVs may not be commonplace for at least several years, I am left wondering what autonomous driving might mean for Boston's commuters - and for the environment.
What are the benefits?
Several potential benefits of the proliferation of AVs spring to mind. As someone forced to contend with aggressive Boston drivers each morning, personally I love the idea of a more relaxed commute free from the eternal question plaguing Bostonians: will there be parking? Beyond personal convenience, AVs would also empower those with limited mobility to get around, reducing inequities in access to jobs, medical care, and other resources.
Studies show that AVs improve safety, as 90% of vehicular accidents occur as a result of human error. Safer roads are great for drivers, but they would also encourage more active, clean mobility like walking and biking. Similarly, by improving driving behavior, AVs can dramatically reduce traffic congestion. Less congestion means shorter commutes and less pollution per trip, benefiting people and the environment.
With clearer roads, MBTA buses and above-ground trains could stick to their schedules and improve service, encouraging an increased use of public transportation. Mayor Walsh has discussed the possibility of using AVs to connect different MBTA lines, improving commutes and likewise increasing public transit ridership.
What are the drawbacks?
However, for every potential environmental benefit AVs present, there could be a large potential drawback. More convenient driving could mean more cars on the roads, even luring would-be MBTA or transit riders away from public transit. People may become comfortable with much longer commutes, increasing traffic and emissions. As AVs replace traditional taxis and transform ridesharing services like Lyft and Uber, empty cars circling the streets could drive up air pollution. Or let's imagine my spouse and I own a private AV, but we work different schedules. I could have my AV drive me to work, send it home empty for my spouse to do the same, then we each separately could call it back at the end of our respective workdays. We just doubled our emissions, and the car was empty for half the time. Reports suggest that non-electrified AVs could increase vehicle travel by 20% and likewise spike carbon dioxide emissions.
So what is the answer?
As with most issues pertaining to transportation in Boston, the answer is complex. Reports suggest that alone, widespread autonomous driving could be detrimental to the environment if all else remains the same. However, in conjunction with a massive shift away from single-occupancy rides, as well as by increasing the availability, affordability, and use of electric vehicles (EVs), autonomous driving can have the positive impact on the environment outlined above. In order for this to happen, it will be critical for policymakers to collaborate effectively with AV companies to promote high-occupancy rides and cost-effectiveness, and to ensure that public transportation remains (or becomes) another viable option for daily commuting. Pending Massachusetts legislation requiring all AVs to be zero-emission would be a great start, should it pass. And its important to note that even with the most optimized system of AVs, it is likely they will never be able to move as many people as efficiently as a good public transit system can. Working with AV companies to promote high-occupancy rides may mean utilizing zero-emission AVs to solve the "first-mile/last-mile" challenge of riding public transit.
It goes without saying that Boston should hasten its efforts to improve transportation and reduce transportation-related emissions. We need to increase the number of bike lanes and make biking a safe option, invest in expanding efficient, clean and affordable public transportation, encourage the use and affordability of electric vehicles, and promote high-occupancy vehicular travel. With these improvements, autonomous vehicles can complement and enhance an already environmentally-friendly transportation system in Boston in a decade or so. Or they could take us in the opposite direction, increasing congestion, pollution, and eroding public transit ridership. The situation we end up with will result from the level of care in planning and collaboration happening now. Let's make sure to create the clean, equitable, accessible transportation future we know is possible.
Carolyn Conley-Das is a Massachusetts Sierra Club Volunteer