Putting Traffic in Its Place: Using the ITE/CNU Design Manual

Now comes the hard part. Putting the new ITE/CNU manual into practice is where--forgive me--the rubber hits the road. Titled Context Sensitive Solutions in Designing Major Urban Thoroughfares for Walkable Communities, the collaborative effort seeks a way forward for practitioners trying to design safe roads and attractive neighborhoods at the same time.

Balancing road capacity with livability has become a widespread goal for communities working to create urban districts that function as high-quality human habitat. Putting Traffic in Its Place was also the topic of a Thursday morning session in which six experts sought to nail down just how to go about using the new ITE/CNU Manual to remake urban thoroughfares.

After all, “placemaking” sounds good down at the coffeeshop, but it’s not so easy to accomplish in the face of the political and financial momentum that drives many road-building projects.

Lately, though, the institutional culture of state DOTs has been changing as fast as the planning context they operate in. Coupled with severe funding shortages, a more flexible perspective has allowed agencies to act on the recognition that large-scale road projects are out of sync with the value they’re perceived to deliver.

So how does a state agency help communities implement the ITE/CNU design guidelines in the midst of constant change? Ask Allen Biehler.

Biehler, Secretary of Transportation, Pennsylania, runs the fifth-largest state highway system in the country, as well as hefty grant programs that fund rail and other transportation modes.

Biehler feels his agency is “just scratching the surface”-—and notes the framing of the problem predetermines the solution. “The whole issue for us has been how do we approach design of our highway system and how have our folks responded. We have a setting in which we’ve trained our citizens to expect that if there’s congestion, we’re going to solve that and have a congestion-free system.”

"But the reality forced us to ask-—what do you really get for it?

Pennsylvania’s milestone came when the State Transportation Commission realized there were $5 billion of projects in process that they could not actually afford to build. They had two choices: either stop work—-or somehow rescale and redesign those projects. Half were stopped, and only three state legislators pitched a fit.

In one case, Diehler and PENNDOT took a 4-lane freeway with three interchanges and downscaled 20% of it into a 45 mph 4-lane arterial and the remaining 80% into a 2-lane road—all in a park-like setting. “We feel like we’re creating a much more livable setting.”

The framing of the question leads to the solution. According to Biehler, "What design manuals lack is an up-front planning piece that sets the stage and defines how this works relative to local communities. When our folks in the design group go back to the office they see this design manual, but they lack this design context.”

Cultural change, in and out of public agencies, are providing some of that guiding context by default.

For Norman Garrick, rediscovering the art of street design is an imperative. Garrick cites Alexander Marshall’s observation that “streets are the bones of the city.” Great cities are built around great streets-—and street networks.

Garrick again: “We can see the need to redesign streets to create a sense of place, the question is, do we still have the skills?"

To Garrick, the ITE/CNU collaboration has produced “a very powerful document—not so much because of what’s in it, but because of what it’s trying to do. Transportation and quality of life is inextricably linked,” he says, “and this is a fundamental shift in how engineers like myself have been taught to think.”

“What we’re going forward with is a different system, and we’re leaving the old one.”

What are we trying to achieve? How do you build good streets? Garrick lists three ingredients necessary to build livable cities that tame traffic impacts--and function as places. These features or operating principles are:

1. A complete and interconnected network of streets;
2. Good streets need to accommodate all users; and
3. All streets are in fact already places; they are not just an invitation to exchange the here and now for greener pastures.

Putting every means of locomotion into the street may violate conventional wisdom. But as Garrick observes, shared through-ways increase safety. Turns out that in places where bikes share the road with cars, traffic fatality rates decrease as the bike-mode share increases. Not just the fatality rate, but the relative severity of the injury decreases as well.


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