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Driverless cars would be a fantastic improvement to society, but I think you might be underestimating how much people will compensate. Traffic rises to fill ro

by bcoates 14y ago

Driverless cars would be a fantastic improvement to society, but I think you might be underestimating how much people will compensate. Traffic rises to fill roads, and only a small part of public transport budgets are for drivers (it looks like around 10% for LA)

surrealize 14y ago
> only a small part of public transport budgets are for drivers (it looks like around 10% for LA) Well, you also have to consider that bus systems are built around driver scarcity. What if buses were half as large, and run twice as often? They can't now, because that would double driver labor costs. If buses were the size of vans, capital costs might even decrease due to having access to van-market economies of scale (the market for vans presumably being significantly larger than the market for buses).
- justincormack 14y ago
  Many countries with lower labour costs this eg the Dolmus in Turkey https://en.wikipedia.org/wiki/Dolmu%C5%9F https://en.wikipedia.org/wiki/Dolmu%C5%9F
  - pekk 14y ago
    Also all over Africa and India. It's a very common pattern outside the weird US
- fulafel 14y ago
  The sensible model seems to be called "flex service" or "demand responsive transit" (1): Dynamically routed small shuttles where customers place trip orders to the transit company, and the routing system figures out paths for the shuttles so customers get where they want to go in reasonable time. (1) https://en.wikipedia.org/wiki/Demand_responsive_transport https://en.wikipedia.org/wiki/Demand_responsive_transport
- eli_gottlieb 14y ago
  You mean share-taxis? They're relatively common already in many places.
Cushman 14y ago
Well, there's no force that makes traffic "rise to fill roads"; there's externalities to having increased traffic capacity that may cause transportation needs to increase. We still have a lot of underutilized roads. The main difference in terms of capacity, I think, is that once we have majority- and fully-autonomous roads, the system will actually not allow the road to exceed capacity. Individual vehicles will respond to signs of lower throughput by getting off of the potentially congested road, while centralized signaling systems will help coordinate routes and departure times to optimize-- and due to the non-Newtonian nature of traffic, keeping throughput high actually increases road capacity. So if you get into your car at 9am and say, "Take me to work," it's not going to say, "Time with traffic: One hour," it's going to say, "We should depart in twenty-five minutes." Even better, if you are subscribed to a service like most Americans will be, you'll instead tell them the day or week or month before, "I need to be at work by 9am," and they'll say, "There will be a fifteen dollar capacity fee. Would you rather arrive at 8:30 or 10?" And let you and your work decide exactly how much of the economy's money it's worth for you to be there at exactly the same time as everyone else in the time zone.
- bcoates 14y ago
  That's way beyond driverless car, that's a global optimization problem. If it were possible, you wouldn't even need driverless cars to implement it. System-to-car communication and slightly more complicated street lights would be enough. For example, many cities already have lit signs that forbid turns from cross-streets onto oversubscribed roads, your nav system could allow you to pay the congestion fee and get authorization to disregard the sign and take the turn. Similarly, you could get out your smartphone and queue yourself to a destination and be told when you get to leave and take the fast route for free. As long as queuing at home got you to your destination faster than queuing in traffic, it would be the individual best strategy to do it and enough people would use it for it to work. The hard part is probably doing traffic scheduling at an acceptable latency, for a city like LA you'd need to model the behavior of millions of cars however many iterations your optimization algorithm needs every few seconds. These kind of problems are really computationally expensive, it may not be economical with current systems and algorithms.

by bcoates 14y ago

surrealize 14y ago

> only a small part of public transport budgets are for drivers (it looks like around 10% for LA) Well, you also have to consider that bus systems are built around driver scarcity. What if buses were half as large, and run twice as often? They can't now, because that would double driver labor costs. If buses were the size of vans, capital costs might even decrease due to having access to van-market economies of scale (the market for vans presumably being significantly larger than the market for buses).

justincormack 14y ago
Many countries with lower labour costs this eg the Dolmus in Turkey https://en.wikipedia.org/wiki/Dolmu%C5%9F https://en.wikipedia.org/wiki/Dolmu%C5%9F
- pekk 14y ago
  Also all over Africa and India. It's a very common pattern outside the weird US
fulafel 14y ago
The sensible model seems to be called "flex service" or "demand responsive transit" (1): Dynamically routed small shuttles where customers place trip orders to the transit company, and the routing system figures out paths for the shuttles so customers get where they want to go in reasonable time. (1) https://en.wikipedia.org/wiki/Demand_responsive_transport https://en.wikipedia.org/wiki/Demand_responsive_transport
eli_gottlieb 14y ago
You mean share-taxis? They're relatively common already in many places.

Cushman 14y ago

Well, there's no force that makes traffic "rise to fill roads"; there's externalities to having increased traffic capacity that may cause transportation needs to increase. We still have a lot of underutilized roads. The main difference in terms of capacity, I think, is that once we have majority- and fully-autonomous roads, the system will actually not allow the road to exceed capacity. Individual vehicles will respond to signs of lower throughput by getting off of the potentially congested road, while centralized signaling systems will help coordinate routes and departure times to optimize-- and due to the non-Newtonian nature of traffic, keeping throughput high actually increases road capacity. So if you get into your car at 9am and say, "Take me to work," it's not going to say, "Time with traffic: One hour," it's going to say, "We should depart in twenty-five minutes." Even better, if you are subscribed to a service like most Americans will be, you'll instead tell them the day or week or month before, "I need to be at work by 9am," and they'll say, "There will be a fifteen dollar capacity fee. Would you rather arrive at 8:30 or 10?" And let you and your work decide exactly how much of the economy's money it's worth for you to be there at exactly the same time as everyone else in the time zone.

bcoates 14y ago
That's way beyond driverless car, that's a global optimization problem. If it were possible, you wouldn't even need driverless cars to implement it. System-to-car communication and slightly more complicated street lights would be enough. For example, many cities already have lit signs that forbid turns from cross-streets onto oversubscribed roads, your nav system could allow you to pay the congestion fee and get authorization to disregard the sign and take the turn. Similarly, you could get out your smartphone and queue yourself to a destination and be told when you get to leave and take the fast route for free. As long as queuing at home got you to your destination faster than queuing in traffic, it would be the individual best strategy to do it and enough people would use it for it to work. The hard part is probably doing traffic scheduling at an acceptable latency, for a city like LA you'd need to model the behavior of millions of cars however many iterations your optimization algorithm needs every few seconds. These kind of problems are really computationally expensive, it may not be economical with current systems and algorithms.