One thing I’d love to see is a chart plotting “percentage of local cars currently in use” against time-of-day. It probably looks pretty concentrated around 9-to-5 commuting hours.
And I found one! For Stockholm at least! Figure 3–4 in Pierre-Jean Rigole’s master’s thesis modeling out robocar impacts:
I confess, I only read the abstract, whose key findings are (emphasis and bullet-pointing mine):
- “The results show that an SAV-based personal transport system has the potential to provide an on-demand door-to-door transport with a high level of service, using less than 10% of today’s private cars and parking places.”
- “In order to provide an environmental benefit and lower congestion an SAV-based personal transport system requires users to accept ride-sharing, allowing a maximum 30% increase of their travel time (15% on average) and a start time window of 10 minutes.”
- “In a scenario where users are not inclined to accept any reduced level of service, i.e. no ride-sharing and no delay, empty vehicle drive of an SAV-based personal transport system will lead to increased road traffic increasing environmental impacts and congestion.”
The simulations which involve ridesharing suggest, in Figure 2–16, around ~8,000 cars would be parked overnight Stockholm, at peak-parking time, down from a baseline of ~135,000. That’s a huge reduction! One thing I’m still missing (I’m not a careful reader) is a count for how many cars are “parked” waiting to pick up their riders during peak-commute. Large employers are probably still going to need big loading zones akin to today’s parking lots. So maybe say they could get away with 20% as much space.
The results for congestion are less striking, in Figure 3–17. Rideshared robocars would mean 6,500 to 7,500 cars on the road during the morning commute peak, compared to a baseline just above 8,000.
I think this doesn’t include an important second-order effect: if you can goof off on your phone or handle work emails instead of driving throughout your commute, you will be less inclined to time your commute in a way that avoids rush hour. So absent some sure-to-be-unpopular incentive scheme, congestion is probably only going to get worse.
Argo, Ford, and fellow robocar enthusiasts may have better simulations of this lying around somewhere, but for now, Rigole’s is the prediction I’m going with.