Be cautious when predicting the future role of AVs
Tuesday, 5 April 2016
Some conclusions from the VTPI report 'Autonomous Vehicle Implementation Predictions'.
Recent announcements that autonomous vehicles (AVs) have safely driven hundreds of thousands of miles, and major manufactures aspire to soon sell such vehicles, and optimistic predictions of their benefits have raised hopes that this technology will soon be widely available and solve many transportation problems. However, there are good reasons to be cautious when predicting their future role.
- There is considerable uncertainty concerning autonomous vehicle benefits, costs and travel impacts. Advocates claim that they will provide large benefits that offset costs, and so advocate policies that encourage their implementation. However, autonomous vehicles will require additional equipment, services and maintenance that will probably increase user costs by hundreds or thousands of dollars per vehicle-year, and many of their benefits are unproven.
- If AVs follow previous vehicle technology deployment patterns, AVs will initially be costly and imperfect.
- During the 2020s and perhaps the 2030s, AVs are likely to be expensive novelties with limited abilities, such as restrictions on the weather and road conditions in which they may operate.
- It will probably be the 2040s or 2050s before middle-income families can afford to own self-driving vehicles that can safely operate in all conditions, and longer before they become affordable to lower-income households on the used-vehicle market.
- A significant portion of motorists may resist such vehicles, just as some motorists prefer manual transmissions, resulting in mixed traffic that creates new roadway management problems.
- Vehicle innovations tend to be implemented more slowly than other technological changes due to their high costs, slow fleet turnover and strict safety requirements.
- Automobiles typically cost fifty times more and last ten times as long as mobile phones and personal computers, so consumers seldom purchase new vehicles just to obtain a new technology.
- Autonomous vehicles will probably have relatively costly equipment and service standards, similar to airplanes, which may discourage some users.
- Advocates may exaggerate net benefits by ignoring new costs and risks, offsetting behavior (the tendency of road users to take additional risks when they feel safer), rebound effects (increased vehicle travel caused by faster travel or reduced operating costs, which may increase external costs), and harms to people who do not to use the technology, such as reduced public transit service. Benefits are sometimes double-counted, for example, by summing increased safety, traffic speeds and facility savings, although there are trade-offs between them.
- Transportation professionals (planners, engineers and policy analysts) have important roles to play in autonomous vehicle development and deployment. To be prudent, infrastructure changes should only occur after autonomous vehicle benefits, affordability and public acceptance are fully demonstrated. This may vary: autonomous vehicles may affect some roadways and communities more than others.
- A critical question is whether autonomous vehicles increase or reduce total vehicle travel and associated external costs. It could go either way. By increasing travel convenience and comfort, and allowing vehicle travel by non-drivers, they could increase total vehicle mileage, but they may also facilitate carsharing, which allows households to reduce vehicle ownership and therefore total driving. This review suggests that they will probably increase total vehicle travel unless implemented with offsetting policies such as efficient road and parking pricing.
- Another critical issue is the degree potential benefits can be achieved when only a portion of vehicle travel is autonomous. Some benefits, such as improved mobility for affluent non-drivers, may occur when autonomous vehicles are uncommon and costly, but many potential benefits require that most or all vehicles on a road operate autonomously. For example, it seems unlikely that traffic densities can significantly increase, traffic lanes be narrowed, parking supply be significantly reduced, or traffic signals be eliminated until most vehicle on affected roads self-drive.
- A key public policy issue is the degree that this technology may harm people who do not use such vehicles, for example, if increased traffic volumes and speeds degrade walking and cycling conditions, conventional public transit service declines, or human-driven vehicles are restricted. Some strategies, such as platooning, may require special autonomous vehicle lanes to achieve benefits. These issues will probably generate considerable debate over their merit and fairness.
- Autonomous vehicle implementation is just one of many trends likely to affect future transport demands and costs, and therefore planning decisions, and not necessarily the most important. Its ultimate impacts depend on how it interacts with other trends, such as shifts from personal to shared vehicles.
Autonomous vehicle implementation, it is probably not a “game changer” during most of our professional lives, and is certainly not a “paradigm shift” since it does not fundamentally change how we define transport problems; rather, it reinforces existing automobile-oriented transport planning.