In the ideal scenario for autonomous vehicles (AVs), traffic congestion is greatly reduced; people unable to afford or operate personal vehicles have access to a new form of mobility for jobs and hospital visits; and cars are able to wirelessly communicate with cities about roadway trash or potholes.
But such broad brushstrokes do a disservice for both policymakers and community members. By overpromising benefits that could be provided through AVs, latent negative externalities could outweigh some of the positives they provide.
The conversation for AVs is largely dominated by personal vehicles, as that is often what people immediately envision when they hear about self-driving cars. Because the vast majority of the public still relies on single-occupancy vehicles for commutes to work or school, it is most present in the public’s conscience. While we're still far from an actualized mass implementation of AVs, it is not hard to imagine a scenario in which people just trade in their current vehicle for a self-driving model.
Without rethinking infrastructure, fuel standards and data sharing requirements, the onset of AVs could yield disastrous results. Because AVs would hypothetically be able to drop off passengers and not require parking, the vehicle could just continue driving on streets until an errand or meal is finished. This scenario would greatly worsen congestion.
According to a set of studies (PDF), 30 percent of the cars in traffic flows were cruising for parking. Perhaps more harmful would be the impact those cars would have on air quality and the environment.
The convergence of the electric propulsion systems and AVs are, in many ways, perfectly aligned. Electric vehicles (EVs) have inherent advantages when it comes to fuel savings and reducing the impact on the environment. Plus, it is also easier for computers to drive electric vehicles.
As part of a testimony submitted at the House Energy and Commerce Committee, the nonprofit dedicated to reducing oil dependency, Securing America’s Future Energy (SAFE), found that “58 percent of autonomous, light-duty vehicle retrofits and models are built over an electric powertrain, while a further 21 percent utilize a hybrid powertrain.”
“Tomorrow’s cars will be safe, green and connected,” Mary Gustanski, Delphi’s vice president of engineering, told Car Talk. “We’re going to see more electrification, and the electric car will merge with automated driving and the connected car.”
Ride-sharing in cities also lends itself to fit the EV/AV equation. Charging station infrastructure is more robust in the urban centers where the testing is taking place. Autonomous fleets of electric vehicles are already being proposed by companies like GM and Uber.
“We see that as very complimentary, technology-wise,” said Harry Lightsey, executive director of emerging technologies policy at GM. “Plus, we really like the idea of being able to put the Bolt out there in a ride-sharing context, and have people experience the vehicle.”
And when a new technology is changing the game like AVs are, "it's a really good opportunity to think about the opportunity to integrate big changes across an entire fleet,” said Corinne Kisner, director of Policy at the National Association of City Transportation Officials (NACTO). Electric and shared-use autonomous vehicles will be most effective when used to deliver shorter, intra-city trips where occupancy can be maximized and vehicles are less likely to be stranded away from charging stations.
One of the biggest hurdles that both electric and autonomous vehicles have faced is cost. Autonomous vehicle technology is still incredibly expensive, said Lightsey. Even with all of the tax credits and subsidies used to encourage the EV market, they are still more expensive than traditional gas-guzzlers. In the long term, however, the per-mile cost to operate these vehicles is projected to be substantially lower.
“Until we get to scale production and economies of scale start to kick in, you could still use the vehicles in ride-sharing because they have the opportunity to produce revenue to offset the capital expense of the vehicle,” said Lightsey.
Vehicle ownership models may also alter the AV andscape. In a typical day, personal vehicles are only in use for 5 percent of the time. The rest of the time, they are parked and taking up space that could be better utilized. If the shared EV/AV model comes to fruition, more space-efficient parking lots could be located outside of urban centers, making more real estate available to develop.
The trends of automation, electrification and ride-sharing reinforce one another. According to a Bloomberg report, urbanization is expected to increase average city density by 30 percent over the next 15 years, stretching existing systems as demand rises.
“It really does not take many additional cars to cause congestion on city streets,” said Kisner, adding that cities must take appropriate steps to avoid more congestion with driverless cars and ensure that the vehicles have a positive effect on the environment.