Re: Travel patterns (was Re: New form of rail transportation)

[amorton@mullian.ee.mu.oz.au (Anthony Morton)]

>> The real question is whether it is a good thing to deliberately engineer
>> more dispersed travel patterns, with a greater emphasis on circumferential
>> travel for its own sake.  I can't myself see any good reason to do this,
>> and plenty of bad ones.

Peter Berrett <pberrett@optushome.com.au> wrote:

>Reasons
>
>1. Dispersal of car traffic means less traffic jams particularly near the
>city
>
>2. Less distance to travel to work
>
>3. Public transport is used more evenly - less crowding
>
>4. More options to get to workplaces

Your argument has a respectable pedigree; it's been put by a number of people
before, most notably John Brotchie at Monash University.  The trouble is that
encouraging dispersal of workplaces does not guarantee people will travel less
distance to work, unless you simultaneously cajole people into living in the
same suburb as where they work.  The only way you can do this is by making it
harder to travel.  People will always have reasons for wanting to live and
work in different parts of the city (hence your reason 4, which indeed
contradicts reason 2), so the actual distribution of homes and workplaces
will always have little to do with average travel distances.

Brotchie himself has also admitted that a dispersed pattern of workplaces
virtually guarantees a reduced 'market share' for public transport.  Having
a predominantly radial pattern limits the number of high-capacity links you
have to provide.  With a dispersed pattern, you have similar numbers of people
wanting to travel between any given origin and destination.  This destroys the
economies of scale that appear when travel is concentrated in corridors.  It
makes travel by private car more attractive but public transport less
attractive, because the services have to be spread more thinly.  Eventually
you wind up with a situation like Los Angeles where traffic jams are worse
than ever, because car dependence has become entrenched.

Which leaves the 'more options' argument.  People will always want to live
where they choose, as they do now.  Inevitably there are pros and cons with
any particular choice of residence, and there's only so much transport
planning can do to make things easier.  Melbourne's radial network is a
reasonable compromise; there's sufficient diversity within most radial
corridors to permit genuine choices.  With a high-quality bus network
providing cross-suburban links, a wider range of choices can be catered for
though at a cost - there is always a cost involved after all.  But there's
only so much choice you can cater for.  To live in Sunbury and work in
Rowville is a silly idea regardless of how much infrastructure you provide.

Cheers,
Tony M.

Public Transport Users Association       http://www.vicnet.net.au/~ptua/