From: rcf@netlink.cts.com (Bob Forsythe)
Newsgroups: alt.planning.urban
Subject: Re: Death and Life of Great American Cities
Date: 10 Jan 93 15:42:23 GMT
Organization: NetLink Online Communications, San Diego CA

karplus@cse.ucsc.edu (Kevin Karplus) writes:

> 
> There is a design that has the advantages of both: provide a grid of
> bike/pedestrian streets, but block them to through automobile traffic,
> except along aterials.  You then have neighborhoods bounded by
> arterials which are internally well connected for bicyclists and
> pedestrians, but which do not have any through traffic.  This can
> often be retrofitted to existing street patterns (either by blocking
> off part of a grid, as has been done in Berkeley), or by adding
> pedestrian and bike passages between cul de sacs (usually harder to
> arrange, since the important rights of way often have houses built
> directly over them, and so can't be acquired with reasonable political
> and economic costs).
> 

     It's quite possible to design developments that use cul-de-sacs so 
that they incorporate internal trail systems, although I'd agree that 
it's more difficult to add them later.  I don't tend to share Calthorp's 
dislike of cul-de-sacs, but most of my experience in planning has dealt 
with estate-lot development more or less out in the boonies of north San 
Diego County.  When a development is 5 miles from the closest commercial 
center, cul-de-sacs don't matter much.  In the center city, (at least 
here) one finds few cul-de-sacs.  It's the suburbs where they exist the 
most, and they are generally a symptom of the larger problem of the 50's 
and '60's view of residential development in large blocks with the shared 
mall concept.  I don't know how that can be addressed, since it such 
development is one *huge* mess.

> Kevin Karplus
> (not a professional planner, but a long time bicycle advocate, who
> sees incompetent or misguided transportation planning as the main
> destructive force in American cities and suburbs)

     I tend to disagree with this (I'm not a transportation planner).  
Transportation planning tends to be reactive rather than proactive.  
Where the problem lies is that roads are designed to accomodate the 
density that is proposed, but once they are built, developers argue for 
higher density based upon the existence of "good" facilities.  The 
consequence are roads that are overloaded due to political decisions that 
go beyond what the transportation planners were told they were originally 
planning for.  For a current Community Plan Update going on in our 
office, the local Planning Group has recommended downgrading virtually 
all the Circulation Element roads (the regional transportation network) 
in their community on the basis that it will hold down growth because the 
Level of Service on them would be such that the GP's Facility Element 
would not allow development.  As the assigned transportation planner 
stated in a hearing on the subject, "if you want less growth, stop 
building houses; downgrading the roads will just make travel that much 
more miserable."  Growth is a function of Zone, General Plan and 
discressionary permit decisions, not road decisions.

-Bob

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