Thursday, February 28, 2013


The following post reflects a Burlington (VT) Walk Bike Council (BWBC) response to member Phil Hammserslough's commending to the Council an interview with community planner Peter Calthorpe....

 Thanks to Phil Hammerslough get us to Peter Calthorpe’s discussion of community design.  This got me to thinking about these two elements: (1)  what is a “walkable” community and this second item from Calthorpe (2) if you want to have a workable transit system you have to “arrive at a place that’s walkable.”


Peter Calthorpe: My short and simple answer is that a well-designed city is walkable. It’s a place where your destinations are close enough to walk to and where you feel safe enough to walk. And it’s a place that is interesting enough socially to make you feel that walking is perhaps something more than just getting from point A to point B. I think that is the heart of it.

……. We have a myopic transportation system. The way we design our communities doesn’t allow walking, doesn’t provide decent transit systems and doesn’t provide alternatives to the car.
London: It brings us back to the idea of walkable communities.
Calthorpe: Exactly. That is the foundation, because if you want a transit system to function, you have to arrive at a place that’s walkable — otherwise you are going to want to take your car there. So you need walkable neighborhoods.

So Calthorpe says our built up areas need to walkable and without “walkability” then transit cannot function (well maybe “function well” might be better).  OK, so what’s “walkable?” How do we measure it?  For us in Vermont, walkable means making existing urban area, town and cities, etc.,“walkable.”  Our populations are generally not growing, there is plenty of opportunity to increase housing densities in our primarily older urban and town centers—we all agree on that.  So, how do we make things “walkable.”  How can we know when something is “walkable?”  And is there a method or way to measure walkability without hiring a consultant?

Interestingly we have, for example, a readily available a way to measure our scenic viewscapes from any vantage point using a simple method which anyone can use—the method not only determines if you have a valuable viewscape but also whether it is among the top few which require every reasonable effort to preserve. And, most important, anyone can do it. The methology, available from the Vermont Agency of Transportation was originally developed from a Massachusetts statewide landscape inventory taken when it appeared the entire state would be overrun by development in the 1950s.  Scenic experts hired by Vermont refined a state methodology using principals the Massachusetts experience and that citizen-usable evaluation tool is available today. Actually a rudimentary method which measures the likelihood a given node, area, corridor affords a workable walking environment.  The method is very simple, probably could use some updating today but gives anyone the ability to determine whether their street, neighborhood and community measure up on a scale of  “walkability”.  (Even Calthorpe abandoned adjusting the word “pedestrian” to “pedestrianability.”)

The walkability measurement method was developed about 1990 as part of the landmark land use/transportation study of the Portland, OR area, a study with the intent to determine how best to develop land and transportation investments to minimize car travel and maximize transit and the active modes of  bicycling and walking.  One of the reports from the 1000 Friends of Oregon sponsored project was a short paper with the bureaucratic title “Pedestrian Environmental Factor.”   A better title might be, “Measuring Community Walkability”—to be referenced here as the “Walkability Study.”  The study itself was not intended to be—nor was it represented—as a yardstick for walkability.  So this analysis takes some liberties with the original report.

The Walkability Study concludes that if you rate four factors on a scale of 0-3 and the total is 9 or better—the area possesses what usually is found in positive walking environments—based on evaluating a large number of locations with a lively walking mode. The four factors are quite easy to determine: (1) presence of a sidewalk; (2) presence of a connected sidewalk network; (3) degree of grades; and (4) ease of crossing intersections.  After using this in examples below, it becomes clear that one might like to rate a factor, for example, 1.5, rather than a whole number so one begins to measure a finer degree of walkability—but dealing with that can be left to another time.

Let’s take a couple of examples in Burlington and determine their “walkability” score using a 0, 1, 2, 3 approach from the Walkability Study.
Church Street Marketplace   Sidewalk:  3  Entire area a walker plaza.
Sidewalk Network:   3  All approaches and exits along the Marketplace involve sidewalks or mall areas
Grade:  3  Some variation exists here—there is a slight grade from Bank Street south to Main Street while Bank Street to Pearl Street is relatively flat.  Overall, given the context and slight grade on one portion of the area, a 3 score appears fair.
Intersection Crossing Ease:  1    OK this is the tough one.  When the Walkability Study was done all U.S. intersections were either signs or signalized—no roundabouts.  Before roundabouts any signalized two-lane roads intersection might get an automatic  score of “1”, a single lane signaled intersection a “2” (two-way stop control also) and 4-way stop intersections a gentleperson’s  “3.”  Purely low traffic residential areas might get a “2” and with a little traffic calming, a “3.”  But the advent of the roundabout and traffic calming techniques changed the equation—for the better for walkers.  Any roundabout reduces delay versus any signalized intersection and safety is improved for walkers at either one or two laners (Vermont at most may have one or two intersections statewide which might require a three-lane roundabout, so they are not a consideration.)

So here goes for a suggested scoring of intersections in the roundabout age.  Generally, from 0 to 3: (1) signalized intersection with one or more legs a four-lane roadway, 0 score; (2) two-lane intersection signalized or two-way stop control, score 1; (3) two-lane roundabout or four-way stop/yield, score 2; and (4) one-lane roundabout with or without traffic calming, score 3.
So, in the case of the Marketplace where there is a mix of two and four lane roadway intersections along north to south boarder streets (Winooski Avenue and Battery Street) , a score of “1” is marked.

College Street and Battery Street  Sidewalk: 3  
Sidewalk Network: 3
Grade: 1 This is a mixture of  a 2 rating south on Battery toward Main, 1 to 2 rating north on Battery and east on College and a 0 rating on College toward the waterfront (the stairway adjacent on the south side gives a concrete picture of the grade). 
Intersection Crossing Ease:  0    Here Battery Street is four lane with a signal—though traffic can be handled by a single lane roundabout which would give it a score of “2”.   This is not to conclude a single lane roundabout is feasible—but since a single lane roundabout ups the intersection score from 7 to 9—below to just into the margin of walkability the impact of the roundabout on walkability becomes clear.  Short of an escalator-like device steep inclines cannot be changed and therefore present a clear barrier to walkability scores.  Even granting the current intersection with  score of “1” leaves it below the desired total score of 9 sought for a  minimum walkability rating. 
North Street and North Champlain  Sidewalk: 3
Sidewalk Network: 3
Grade: 3
Intersection Crossing Ease:  2     This is an interesting intersection as it does have a signal which—based on he above discussion would be scored only a “1”.  But in this case North Champlain—a one-way north from Pearl Street—is traffic calmed so one can credit the intersection with an extra point.  The suggestion here is that a signaled intersection involving two-lane streets with full traffic calming could reach a score of  “3” equal to a single lane roundabout.  Most likely before that would occur one would simply convert the intersection to a roundabout and remove the signal.

This represents a first cut application.  The raw total scores do in fact point to where attention needs to be given. 

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