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Why driverless cars may mean jams tomorrow

economist.com

21–30 of 77 posts

Re: Why driverless cars may mean jams tomorrow

#21

This article seems to offer a somewhat limited vision. Personal, driverless cars may mean as many jams as today. What about "ride-sharing" driverless systems, where many people share the same car/minivan in an automated fashion, reducing the number of vehicles on the road and the need for parking? That would make, IMHO, the best compromise between mass transit (effective, but inflexible to people needs) and personal…

Still, the author observes that, generally, a more efficient system will boost economy and increase the quality of life, which will again attract more "users", until it becomes again unbearable.

Re: Why driverless cars may mean jams tomorrow

#22
post #7
post #2

This title is confusing. The actual title is more approachable - Why driverless cars may mean jams tomorrow Still I am confused by articles logic - Why would driveless car be any better than the current ownership model? The logic presented is - AIs that can pilot cars more closely together will boost road capacity . But using article's logic on people movement - it might entice people who actually don't drive due to…

I also don't follow that argument. IMHO accidents and bad swarm behavior (people following too closely, switching lanes too often, accelerating and braking too much) lead to traffic jams. If we can get that improved our roads could take twice the cars.

More, even. Driving into SF at rush hour is an exercise is mostly about being stationary with occasional jerks forward. You could improve that throughput a hundredfold if things could keep moving.

Re: Why driverless cars may mean jams tomorrow

#23
The odds are that self driving cars will stick to the posted speed limit, and that those limits will not be raised. This will reduce the available capacity of many interstate grade roads, as the posted speed is often unsafely low. On the roads around here, the accepted and safe speed is often around 70mph, but the posted speed is often 55mph.

https://www.motorists.org/blog/speed-limits-slower-safer/

Additionally, self driving cars appear to have a higher accident rate per mile driven (5x). This appears to be at least partly the result of the self driving cars performing unorthodox maneuvers in some situations.

Re: Why driverless cars may mean jams tomorrow

#24
post #17

This article seems to offer a somewhat limited vision. Personal, driverless cars may mean as many jams as today. What about "ride-sharing" driverless systems, where many people share the same car/minivan in an automated fashion, reducing the number of vehicles on the road and the need for parking? That would make, IMHO, the best compromise between mass transit (effective, but inflexible to people needs) and personal…

You mean sharing a ride like say a big, long vehicle with lots of seats that visits a number of stops on a route? Yeah, that would be a great idea. We could improve this even further by giving the ride-share vehicle it's own lane, then turn both the wheels and the road surface into metal to reduce friction. BRB, going to the patent office... Not to be too snarky, but as a non-american it has been amazing to watch the…

I'm not american, and I use public transport in Italy. But the public transport is simply ineffective a) from a door-to-door timing perspective and b) from a flexibility perspective.

Sure, I don't live in a big city, so maybe the public transport is not as effective as it could be; but many people I spoke with even in London (and other places like Berlin, Paris, Milan) seem to share the same suffering: constantly using public transport ONLY is annoying. Unless you plan your life now & forever (e.g. you buy an house on the right subway line to your job, and never change jobs) you'll find a moment when it's hard to do what you'd like to do. Want to go to the gym? Ouch, the last subway ride ends before you'd go out. Need to collect your kids before going home? No luck, their school is in a badly-served zone.

That's the issue with public transit.

Re: Why driverless cars may mean jams tomorrow

#26
post #7
post #2

This title is confusing. The actual title is more approachable - Why driverless cars may mean jams tomorrow Still I am confused by articles logic - Why would driveless car be any better than the current ownership model? The logic presented is - AIs that can pilot cars more closely together will boost road capacity . But using article's logic on people movement - it might entice people who actually don't drive due to…

I also don't follow that argument. IMHO accidents and bad swarm behavior (people following too closely, switching lanes too often, accelerating and braking too much) lead to traffic jams. If we can get that improved our roads could take twice the cars.

You don't get the point: if you create an empty space on the roads (whatever solution you invent), people will start occupying it immediately, and you face the same problem again.

Re: Why driverless cars may mean jams tomorrow

#27
Jams are caused by human drivers whose slow reaction time causes waves of slowdowns that build up into complete stoppage.

We can get AI reaction time down to the speed of light since all vehicles can communicate their speed, direction, and location simultaneously.

It is a totally new epoch of transportation and the old rules no longer apply.

Re: Why driverless cars may mean jams tomorrow

#28

This article seems to offer a somewhat limited vision. Personal, driverless cars may mean as many jams as today. What about "ride-sharing" driverless systems, where many people share the same car/minivan in an automated fashion, reducing the number of vehicles on the road and the need for parking? That would make, IMHO, the best compromise between mass transit (effective, but inflexible to people needs) and personal…

Nobody really likes ride sharing, though. That's why people drive in the first place.

I can imagine a world where instead of having a car you have a dedicated seat on your cul-de-sac's station-transit. Maybe set up in pods like a one-person version of compartments on 1930s trains.

Re: Why driverless cars may mean jams tomorrow

#29
post #17

This article seems to offer a somewhat limited vision. Personal, driverless cars may mean as many jams as today. What about "ride-sharing" driverless systems, where many people share the same car/minivan in an automated fashion, reducing the number of vehicles on the road and the need for parking? That would make, IMHO, the best compromise between mass transit (effective, but inflexible to people needs) and personal…

You mean sharing a ride like say a big, long vehicle with lots of seats that visits a number of stops on a route? Yeah, that would be a great idea. We could improve this even further by giving the ride-share vehicle it's own lane, then turn both the wheels and the road surface into metal to reduce friction. BRB, going to the patent office... Not to be too snarky, but as a non-american it has been amazing to watch the…

I think you're not seeing the full potential of such a system. Public transportation for now is very useful but over large distances can involve many changes, waiting times and inefficiencies. We could have a swarm of driverless cars taking in all passenger requests and computing the optimal dispatching of driverless cars. For instance pick up passenger A and B, drive to place C and drop off B who gets has another driverless shuttle pick him up a minute later, pick up customer D and drive to E. Since all shuttles would be aware of each other's locations, they can take that into account into the schedule computation and avoid jamming streets.

Re: Why driverless cars may mean jams tomorrow

#30
post #17

This article seems to offer a somewhat limited vision. Personal, driverless cars may mean as many jams as today. What about "ride-sharing" driverless systems, where many people share the same car/minivan in an automated fashion, reducing the number of vehicles on the road and the need for parking? That would make, IMHO, the best compromise between mass transit (effective, but inflexible to people needs) and personal…

You mean sharing a ride like say a big, long vehicle with lots of seats that visits a number of stops on a route? Yeah, that would be a great idea. We could improve this even further by giving the ride-share vehicle it's own lane, then turn both the wheels and the road surface into metal to reduce friction. BRB, going to the patent office... Not to be too snarky, but as a non-american it has been amazing to watch the…

No, not like that. Trains work well for arterial routes that need to carry large volumes of people along predictable corridors at predictable times of day -- eg., for commuting. And yes America certainly needs to get better at investing in them.

But trains don't work at all well for serving smaller volumes of people moving in stochastic patterns at arbitrary times of day. Neither do buses. Cars serve this need very well -- they also generate massive negative externalities in the process, but they do serve this need.

Why should we care about "people moving in stochastic patterns at arbitrary times of day"? Transport planners call this "incidental travel," implying that it isn't really significant. But this is because transport planners don't have a good means of addressing it. In fact, incidental travel actually the majority of trips that people take: going shopping, visiting friends, going to the doctor's, eating out, etc. The balance is about 60/40 for incidental travel / commuting.

People own cars to serve this need, because nothing else will (unless you're in a mega-city that can afford to run high-frequency mass transport 24/7). Then, since car ownership is a sunk cost, people use their cars for commuting as well, where they're really sub-optimal.

Travel demand is an incredibly heterogeneous problem, which can only be addressed with a hierarchy of modes. That includes mass transport at fixed schedules, individual transport that is on-demand, and intermediate collective transport modes that currently doesn't really exist. Autonomous vehicles with 4-8 person capacities and demand-responsive routing would solve a broad class of transport problems that conventional public transport cannot -- and could do so without many of the negative externalities of private cars.

I've written much more on the subject, if you're interested: http://archive.podcar.org/blogs/nathan-koren/article/news/th...

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