Imagine you’re driving in London or New York, inching slowly through patience-testing traffic. You look to your left, peer into the car next to you, and see that there’s no one there. You look to the other side and notice there’s no one inside the car to your right either. This is a future we can expect: rows of driverless gridlock, empty cars slowly roaming the city, dutifully cruising until their owners get out of work, all in the name of avoiding expensive urban parking fees.
In a recent publication in Transport Policy, Adam Millard-Ball and his colleagues at the University of California, Santa Cruz illustrate possible alternatives that autonomous vehicles can use instead of parking.
Society doesn’t seem to have made up its mind on autonomous vehicles. According to a Pew Research Center study, Americans are both enthusaistic and worried about their adoption. In academia, scientists have split opinions on whether future driverless cars will positively or negatively affect the environment. On the one hand, driverless cars fuel urban sprawl, but since their design optimizes spatial efficiency, they are also seen as an opportunity to redesign cities to promote walking and cycling.
In the face of future ambiguity, there is one clear consequence of the adoption of autonomous vehicles: the effect on traffic. An inevitable but rarely addressed aspect of these cars is their ability to bypass expensive parking fees in ways that increase drive times and worsen already rising urban congestion.
One option is to send the car home after the passenger is dropped off. While this may seem like a harmless high tech chauffeur, there are distinct environmental costs to this practice. The number of trips the car takes is doubled, resulting in more congestion and more vehicle emissions per person.
Another, more eerie option, is called cruising. After the passenger is dropped off, the car drives around the city as slowly as possible so as to minimize fuel costs. Instinctively, the cost of driving all day seems higher than parking in a city. But Millard-Ball’s study found that it is by far cheaper than parking, costing less than 50 cents per hour in contrast to the $4 per hour cost of parking in many large cities.
Also, when multiple cars engage in cruising, each with the incentive to go as slowly as possible, the chance of gridlock is high. Picture hundreds, even thousands of cars, sitting in the middle of residential streets, waiting patiently for the return of their owners. Even in relatively small numbers, less than 4,000 autonomous vehicles are needed to slow some streets down to under two kilometers per hour.
This traffic nightmare comes with a breath of solace in its possible solutions. Free or subsidized peripheral parking, similar to the cell phone parking lots in airports, can encourage more sharing of AVs and limit congestion within cities.
It has also added credence to the proposition of municipal congestion pricing, a policy that has also been proposed as a response to the increased traffic caused by ride-sharing companies like Uber and Lyft. Without the offset of congestion pricing, cities stand to lose a significant portion of their municipal revenue from the decrease in parking popularity. For example, in 2016, New York City made $545 million in parking fines, a significant potential loss if not remedied by the approval of congestion charges.
While the adoption of autonomous vehicles seems inevitable, we can’t know exactly how our cities will look when autonomous vehicles gain popularity. We can only hope that the traffic they bring doesn’t add to our road rage.
Tara Jayaram is a senior in LSA.