[sustran] Re: mobility as a right

[Chris Bradshaw]

[Sorry about not jumping earlier]

I agree that _mobility_ must be distinguished from _access_.

Access is the movement away from one place and the arrival at another;
mobility is the movement between the two places.  Access is therefore what
the traveller seeks, but mobility is what they need in order to _effect_
access.

The roads hierarchy, unfortunately, puts mobility ahead of access by
requiring movements in and out of destinations to become secondary to those
along the main roads.  In that way, the hierarchy favours a smaller number
of long trips over a large number of short trips.

Further, the middle of a trip (when the traveller is moving the fastest and
is impeded the least, usually on a wide, fast road, or on the largest,
fastest transit vehicle), his movement interferes with the access movements
into and out of the places adjacent to that roadway.  For that reason, the
land uses that are most sensitive to such impacts are located as far as
possible from the upper-hierarchy corridors.  This is both to buffer the
land use from noise, dirt, and danger, but to provide a mini-hierarchy of
roads and lanes to buffer the high-capacity roadway from the slow,
pedestrian-oriented parking-space access or drop-off point.

In many ways, when people choose to live in a dense city, they are choosing
access over mobility (many short trips over a smaller number of faster
trips).  For this reason, city planning thwarts the satisfaction of access
by turning roadways adjacent to destinations into wide speedways.  The most
successful cities either bury such corridors or just don't provide them,
letting those wanting to make long, fast trips to suffer with many delays,
thus discouraging such movements (and therefore thwarting sprawl).

Walking, in this thinking, is the most access-oriented mode.  Not only does
every trip require walking in its two access phases, but when walking is
used in the middle for mobility, it will never infringe on access movements
into and out of the destinations along its way.

Chris Bradshaw
Ottawa