[LINK] Why you may not own, or drive your vehicle in 10 years time

[David Lochrin P]

On 2016-06-08 17:49 Chris Johnson wrote:

> There are too many posts to quote from - but consider, just on whether all cars should have a self-driving function. Two cases:
> 
> 1. If arterial roads such as the Sydney M5 Eastern Distributor/Hume Highway mandated hands-off driving only - and required human drivers to use the alternative multiply traffic-lighted slow routes - now there's an incentive to have and use a self-driving car some of the time.  The public benefit of automated arterial roads would be a lower accident rate (we presume) and a closer packing density, increasing the carrying capacity more cheaply than building another tunnel.

I agree this may be where it's heading, so let's think it through.

It seems peak-hour problems on the Hume Highway / M5 arise mainly where speed limits decrease from 110 to 80 Kph or large volumes of traffic converge, and this would be equally true for driverless and conventional vehicles.  In essence, the throughput of the system is only as good as the throughput of its slowest part, which is all basic queueing theory.

However we could still expect some improvement in throughput.  Minimising the "shock waves" from stop-start traffic would certainly help (ever been crawling along in heavy traffic when suddenly it all speeds up for no apparent reason?).  Whether the possible improvement in traffic flow and lower accidents would justify the administrative costs or be politically acceptable (because users would have to own a compliant vehicle) is questionable.

Perhaps we could introduce another level of complexity and have the driverless vehicles communicating either between themselves or with a supervisory controller, which complicates the queueing theory a little.  While that might increase the throughput, it would greatly increase the complexity and therefore the vulnerability of the whole system.

Then of course there's the question of what you do with these vehicles when they arrive at their destination.

And accidents would inevitably happen, especially if non-driverless vehicles (maybe certain commercial & emergency vehicles) are allowed.  This is where the tradeoff between efficiency & vulnerability really matters - any accident might be a ripper!  If Bloggs Removals causes a 100-car pileup their insurance company would not be happy vegemites, though their lawyers might be.

I've never had anything to do with traffic management, but I am a frequest user of the Hume/M5 road.

David L.