Parking lots: Why autonomous cars could save acres of space

Parking lots: Why autonomous c...
Autonomous vehicles will be able to pack themselves like sardines
Autonomous vehicles will be able to pack themselves like sardines
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Left to right:  University of Toronto researchers Sina Bahrami, Mehdi Nourinejad and Professor Matthew Roorda
Left to right:  University of Toronto researchers Sina Bahrami, Mehdi Nourinejad and Professor Matthew Roorda
Autonomous vehicles will be able to pack themselves like sardines
Autonomous vehicles will be able to pack themselves like sardines

Autonomous cars could prove to be splendid news for parking, according to new research from the University of Toronto. Because self-driving cars can park themselves, you can get out beforehand. Since you don't need to open the door once parked you can cram many more cars in. But according to the researchers, if autonomous cars work together, even more space can be saved – though perhaps not surprisingly there's a trade-off to think about too…

"In a parking lot full of AVs [autonomous vehicles], you don't need to open the doors, so they can park with very little space in between," explains Professor Matthew Roorda, an author of the new research. So far, so intuitive: you can save space in a car park by cramming the cars like sardines, which self-parking cars allow you to do.

But autonomous cars can potentially go further. "You also don't need to leave space for each car to drive out, because you can signal the surrounding AVs to move out of the way," Roorda adds. So rather than having parking islands two cars deep, they can be much larger grids with many rows and columns of spaces. Cars parked near the middle will be able to tell the cars needed to move out of the way.

Inevitably, there's a balance to strike. "If you have a very large grid, it leads to a lot of relocations, which means that it takes longer on average to retrieve your vehicle," says co-author Mehdi Nourinejad. "On the other hand, if you have a number of smaller grids, it wastes a lot of space." Clearly, if your car's parked 10 rows deep, there's going to be a wait while nine cars make way.

To work out the best balance of parking space and time to park and get out, the researchers made a computer model to test different layouts. Their analysis showed that, in a square parking lot, it's possible to make room for up to 87 percent more cars than normal. However, factoring in waiting times, the team thinks an increase of 62 percent is the sweet spot.

Not that a parking lot needs to commit to any one layout. "If demand changes – for example, if you need to pack more cars into the lot – you don't need to paint new parking spaces," Bahrami adds. "Instead, the operator can just signal the cars to rearrange themselves. It will take longer to retrieve your vehicle, but you will fit more cars in."

Left to right:  University of Toronto researchers Sina Bahrami, Mehdi Nourinejad and Professor Matthew Roorda
Left to right:  University of Toronto researchers Sina Bahrami, Mehdi Nourinejad and Professor Matthew Roorda

Of course, with a self-driving car, you don't even need to go to the parking lot. Simply get out at your desired location while your car trundles off to park. But there's a potential down-side to this, according to the researchers. The parking lot may benefit, but roads may not.

"Right now, we have a lot of cars on the road with just one passenger," Roorda explains. "If we locate AV parking lots too far away from major attractions, we could end up with streets crowded with vehicles that have zero passengers, which would be worse."

There are two obvious benefits to all of this: squeezing more cars into an existing parking lot, or reducing the size of parking lots to meet the same demand, freeing up valuable land – particularly in cities. Of course, the approach requires 100 percent of the cars to be autonomous, so don't expect your local parking lot to be re-planned any time soon. But the researchers point out that a car park with separate autonomous and non-autonomous parking areas would be one possibility when the demand is there.

The team's research, Designing parking facilities for autonomous vehicles, is published in the journal Transportation Research Part B: Methodological.

Source: University of Toronto

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The more sophisicated the optimizing strategy to increasing parking density, the more each car will have to rely on the optimal workings of all cars around it. If a car on the perimeter of a mass of parked car malfunctions or gets hacked, all the cars dependent on its moving properly are trapped - for how long? I guess I'm a luddite regarding this technology; not threatened, though, so much as wary. What about hacked and disabling attacks like a massive EMP strike? The more complete the automation, the more complete the consequences of disruption. How are we doing on protecting ourselves from hacking, randomware attacks, and the like? Get serious.
This is hardly worthy of an academic exercise. If cars can park themselves, then parking up to a mile away after you are dropped off is no problem because you don't have to walk the distance. The benefit to cramming more cars into a lot would be to reduce the walking distance. That doesn't apply.
When I go to a shopping mall quite frequently I return to my car and 'dump' some of my shopping to save having to lug it around while I continue to shop. The prospect of trying to do this when my vehicle has to be 'shuffled' out from the middle of a tightly bunched 'sea' of cars would be unthinkable - so I for one would want much easier access to my vehicle and not a 20 minute wait until my car gets to the front so I can just open a door and throw in a few heavy bags. Technology is supposed to make life better ...isn't it?
And here I thought that AV's would lead to greatly reduced private ownership of cars anyway, leading to far less demand for parking spaces (since personally owned cars are typically left unused 95% of the time, but always-used on-demand Uber-like cars will have little need for long term parking). So all of this would seem to be a solution in search of a problem.
I think @f8lee has a valid point here. With fully working 100% autonomy to the extent that cars can drive on roads with no drivers it seems like many people will just have someone else's available car drive them to work, drop them off, and leave to pick up someone else. The cost of car ownership would be split between a dozen people using the vehicle each day and parking lots would have a smaller burden. To the researchers point though it would lead to empty vehicles adding additional traffic on roads with trips to retrieve passengers (like with taxi's) functionally shifting the burden from parking lots to roads.
In addtion to the effect mentioned by f8lee, where some cars are not parked at all, the study should note that smaller cars actually take less room, where it's not required that all parking spots are the same size. Also, for "Alien", please get a shopping cart. The malls that will do this kind of parking have already heard and the carts will be provided.
Your car could go off to work for Uber/Lyft, etc., too. It could be earning you money while you work...
Maybe I'm just selfish, but I want my own car. Not sharing a car with a bunch of stinky, flu sneezing and who knows what else they've been doing in a self driving car with no one else in it. I want it to drive itself whenever I want it to, and I want it to prevent me from getting in any crash if I'm driving it.