New urbanists call for changes in ITE guide to “context-sensitive” design
A long-awaited thoroughfare design manual — the fruit of some five years of collaboration between the Institute of Transportation Engineers (ITE) and the Congress for New Urbanism — will go through its final approval phase this year. The result could be an important step forward for street design — or it could be a setback, possibly a serious one. Much depends on whether the manual’s sponsors accept key revisions that new urbanists are pressing for.
CNU’s fourth “transportation summit,” held in November in Boulder, Colorado, brought out strong arguments for altering what new urbanists generally see as a flawed but potentially beneficial document. The manual, Context Sensitive Solutions in Designing Major Urban Thoroughfares for Walkable Communities, is scheduled to be approved or rejected by ITE as a “recommended practice” by the end of 2007 (see March 2006 New Urban News).
The main points of disagreement are these:
• The proposed manual continues the usual transportation engineering practice of designing roads that would carry traffic faster than the posted limit and faster than many communities — and their vulnerable pedestrians — want. For example, when the “target speed” (the desired operating speed) for traffic is 30 mph, according to the manual, the road could be designed to function at 35 mph. This encourages speeding, and is hazardous to pedestrians, whose death rate skyrockets as the speed of vehicles increases.
“Above 30 mph, you’re killing about 55 percent of the pedestrians who get hit,” said Billy Hattaway of Glatting Jackson consultants in Orlando. “The target and design speeds should be the same. I would go to as low as 20 mph; no higher than 35.” Norman Garrick, a University of Connecticut civil engineering professor and co-chair of CNU’s Project for Transportation Reform, agreed that controlling speed is essential. “A pedestrian has a 5 percent chance of being killed at 20 mph,” he said, “and an 85 percent chance of being killed at 40 mph.”
• An entire chapter lays out standards for roads that are oriented to motor vehicles but not to pedestrians — they’re called ”thoroughfares in a single land use or vehicle mobility priority areas.” This “contradicts the purpose of the manual” and “should be removed,” CNU’s Executive Committee wrote the ITE in a Dec.18 letter that also asked for other changes dealing with speed and other issues. It’s feared that the chapter may give transportation engineers the impression that designing for pedestrians and communities is merely an option, not a necessity.
• The manual introduces a hierarchy of context zones, mainly from Context Zone 3 (suburban) through Context Zone 6 (urban core), to help traffic engineers see how the roads should relate to their surroundings. Attention to context is one of the major advances the manual offers, but some would rather have the manual use the new urbanist term “Transect zone.”
“The Transect should be mentioned, and Context zones should be labeled as T zones,” not C zones, Rick Hall of Hall Planning & Engineering in Tallahassee told several dozen new urbanists and transportation and planning specialists during their final day in Boulder. “There are already thousands of professionals talking about Transect zones.”
• The manual continues to use the “functional classification” terms of conventional traffic engineering, such as “collector” and “arterial,” which arose, Hall says, during a period in which walking was regarded as an obsolete means of getting around. Critics see the manual’s combination of functional classification and new urbanist terms as a half-step that invites confusion.
Many said it would be better simply to adopt the terms that new urbanists prefer, such as “boulevard” and “avenue” — names that refer to thoroughfares serving more than motorists. The writers of the manual “melded two concepts in a way that makes no sense altogether,” Garrick declared. “Let’s get the melding of functional classification and thoroughfare design out of the document.”
• Traffic lanes are treated in a manner that could lead to their being too wide, encouraging speeding and endangering pedestrians. “We need to be able to go to 9-foot lanes on major thoroughfares,” Hattaway said. Lucy Gibson of Vermont-based Smart Mobility said the manual “calls for Level of Service C; it means adding so many lanes that there’s no walkability.” She and Norm Marshall, Smart Mobility’s president, intend to develop a checklist of issues to examine.
Boulevard expert Elizabeth Macdonald of Jacobs Macdonald: Cityworks in the San Francisco Bay Area said the manual’s presentation of multiway boulevards “is not nuanced enough” and could produce bad, overly wide boulevards. She recommended removing boulevards from the manual entirely.
Rick Chellman of New Hampshire-based TND Engineering has been designing streets for traditional neighborhood developments probably longer than any other new urbanist transportation specialist in America. “I fear that the way the manual is presently laid out technically will simply reinforce the same old wrong thinking,” he told New Urban News. “The functional classification problem is strategically wrong; the technical details are tactically in error; and the universal reliance on existing AASHTO [American Association of State Highway and Transportation Officials] documents will only underscore to ‘those guys’ [the overwhelmingly male transportation engineering profession] that they are just fine, thank-you very much.”
Another longtime transportation specialist, Peter Swift, who expects to return in January to the Middle East, where he is director of town planning for Mid Atlantic Enterprises, told New Urban News that the manual “is a step in the right direction” but suffers from “some serious deficiencies.”
DFENSE OF THE MANUAL
Despite the strong criticism, many said they expect the manual to be helpful after it is revised and approved. “How to get back to making great streets in America” is the goal, Garrick said. “This document is a step in that direction,” and has spurred useful collaboration between engineers and urban designers around the nation. Urban designer Marcy McInelly, co-chair of the Project for Transportation Reform and president of Urbsworks in Portland, Oregon, praised the manual for addressing transportation design at the scale of the neighborhood, district, and corridor.
Garrick told New Urban News that the worst problems spring from the manual’s inclusion of troubling details such as overly large corner turning radii — specifications that “don’t add up to good urbanism.” He warned, “These are the issues that will haunt urbanists that are trying to use the document to support good urban design in the field.”
“There are at least 50 items where we had some disagreement,” Bochner explained. Through consensus, decisions were reached on two-thirds of them. McInelly said the term “context zone” was chosen because it can serve as an effective transition for people unfamiliar with the Transect. Brian Bochner of the Texas Transportation Institute supported McInelly, saying, “In the engineering field, the Transect and context are not understood.”
“The case studies will be one of the best features of the manual,” said Dan Burden of Glatting Jackson.
NEXT MOVES
The period for submitting comments on the manual officially ended Dec. 31, but Bochner said that if people send comments in the first few weeks of this year to Lisa Tierney at ITE (ltierney@ite.org), they will be reviewed. About 50 individuals or organizations submitted comments by Dec. 31. Bochner described the manual as “a semi-final report … the last end of a public involvement process,” and said that in 2007 “we want to refine this and make it even better.” A revised draft is expected to be produced by mid- to late 2007.
If the manual is approved, it will then be up to officials in the 50 states and thousands of local governments as to whether to apply its techniques in their jurisdictions. An outreach effort will be conducted to encourage adoption of the recommendations. “We’ll know it’s implemented when it’s used widely,” Bochner said. The intended users include transportation and civil engineers, transportation planners, land-use professionals, design professionals, and public officials.
CNU vice-chair Jacky Grimshaw said the originators of the manual were CNU, the Federal Highway Administration, and the US Environmental Protection Agency. The ITE became a partner in the effort because it is an organization that establishes and disseminates transportation standards. The manual is available free at www.ite.org. A printed copy can be obtained for $25.
Valerie Taylor of Nelson/Nygaard consultants announced during the summit that a white paper will be produced on how to resolve conflicts between oversize vehicles — such as buses, emergency vehicles, and garbage trucks — and traditional streets. The white paper will include case studies and intersection templates.
This article is available in the January/February 2007 issue of New Urban News, along with many more articles not available online. Subscribe or order the individual issue. |
