XPost: rec.arts.sf.written, rec.arts.sf.science   
   From: jclarkeusenet@cox.net   
      
   In article , bap@shrdlu.com says...   
   >   
   > On 14/01/14 13:45, J. Clarke wrote:   
   > > In article , bap@shrdlu.com says...   
   > >>   
   > >> On 14/01/14 03:21, Robert Bannister wrote:   
   > >>>> I know train fans love trains, but the fact is that the circumstances   
   > >>>> under which they make economic sense are limited.   
   > >>>>   
   > >>>   
   > >>> That's what the conservatives said about rail in my city. Now the   
   > >>> no-longer-quite-new trains are packed and are much faster than you could   
   > >>> possibly drive and cheaper than using a car. It's the parking at the   
   > >>> train station that is the problem.   
   > >>   
   > >> It's certainly true that trains are more easily justifiable when   
   > >> population densities are high. But foreseeable changes might alter   
   > >> population-density in the US. If the cost of energy continues to rise it   
   > >> will tend to encourage energy-efficient use of land. That could involve   
   > >> reducing the size of cities so that the majority of the population can   
   > >> use trains.   
   > >   
   > > ???  The places in the US where trains work are New York, Chicago, and   
   > > DC, all of which have very high population densities.  Lower population   
   > > density means that trains don't work because you don't get enough   
   > > ridership to support the cost.   
   >   
   >   
   > Sorry, I wasn't clear. By reducing the size of cities I mean abandoning   
   > the suburbs and moving all of the population into the centre. Reducing   
   > the physical size of the city but leaving the population.   
      
   And how do you convince the suburban dwellers, who do not want to live   
   in the city core (if they did want to they already would) to move into   
   the city core?   
      
   > >> Self-driving cars could be a part of a larger integrated   
   > >> transport system. Less energy-efficient than having to walk to a bus   
   > >> stop but more efficient than using individually owned cars.   
   > >   
   > > The efficiency increase of a self-driving car would be minimal--the   
   > > difference between cruise control and no cruise control.  All the   
   > > schemes I'm seeing touted on this thread to use them like taxicabs with   
   > > one car serving multiple people would not increase efficiency, it would   
   > > decrease it because the car is running around all over the place   
   > > repositioning itself.   
   >   
   > No, that's not necessarily so. The car's utilisation would increase   
   > because it wouldn't be spending as much time idle.   
      
   If a car consumed no resources during operation then "increased   
   utilization" would be beneficial.  However the major operating cost of   
   car is the energy to run it.  Any time you move it, whether full or   
   empty, you are consuming energy to do so.  So if I take a car in to   
   work, and then it drives home, the wife takes it shopping, and then it   
   drives back to work to pick me up, it's made two unnecessary long trips   
   and consumed the fuel for those trips.  For me it's the difference   
   between $160/month and $320/month for gas.   
      
   > It's total mileage   
   > would also be much lower because it only needs to transfer passengers to   
   > a hub where they can switch to and from more efficient transport modes.   
      
   Why would the "total mileaage" of a self-driving car "taking people to a   
   hub" be lower than the "total mileage" of a regular car taking the same   
   people to the same hub?   
      
   You are interjecting other means of transportation than self-driving   
   cars now and claiming that those other means of transportation are   
   benefits of self-driving cars.   
      
   > If my pod suggestion was used they wouldn't even need to get out of the   
   > pod as it switched from road to rail.   
      
   You're assuming that God is going to turn all cars into self-driving   
   pods overnight.  It's not going to work that way.  Any changes in   
   infrastructure are going to have to accomodate both self-driving and   
   non-self-driving cars and they are not going to confer benefit for your   
   "pods" until enough people are driving "pods" to make pod-trains or the   
   like cost-effective.  But since without the pod-trains the pod-cars make   
   no sense at all, they aren't going to happen.   
      
   > >> Of course there is also the safety issue. If we continue to be more   
   > >> risk-averse then manually driven cars might be banned or more likely   
   > >> discouraged by higher insurance costs.   
   > >   
   > > This is concievable.   
   > >   
   > >   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)