The Inappropriateness of Highway Design in a City

 

By Dom Nozzi

There is a big problem in the roadway design found in Boulder, Colorado. Too much of the design has an inappropriate “highway” orientation.

This is incompatible with what a city needs to be healthy and safe.

Exemplifying this is a dedicated right-turn lane in central Boulder (for those of you who live in Boulder, it can be found on Raleigh onto Broadway southbound). This lane – because it creates excessive asphalt width for motorized vehicle travel — inevitably promotes excessively high motor vehicle turning movements and promotes inattentive driving by the turning motorist. Without removing that right turn lane, in my opinion, this intersection will remain a dangerous intersection.

As long as Boulder continues its counterproductive, decades-long, highly expensive efforts to convenience cars, this city will remain a very dangerous place for travelers and will fail to achieve its newly adopted “Vision Zero” objective, regardless of how much we install more safety lights, safety paint, safety signs, safety enforcement, and safety education. There is no win-win when it comes to cars.

And Boulder continues to fail to understand that.

There are serious negatives to double-left turns (and their highway cousins, the dedicated right-turn lane and the slip lane).

Of course, double-left turn lanes also destroy human scale and a sense of place. A double-left turn lane intersection will never feel like a place to hang out because it vastly exceeds human scale. These over-sized intersections are so hostile that they obligate property owners at each of the four corners of the intersection to pull back from the intersection with massive setbacks, large asphalt parking lots, and auto-oriented land uses that can tolerate such an unpleasant atmosphere (such as a gas station). This sort of deadening creates an area of apparent abandonment, and is the antithesis of what a city needs for health.

Ultimately the double-left turn intersection fails to induce nearby land uses that will generate tax revenues sufficient to make this part of the city self-supporting. It becomes an on-going financial liability that will forever drain substantial dollars from the city budget

The enormous size and relatively high motor vehicle speeds induced by a double-left turn intersection creates dangerous and intimidating conditions for bicyclists and pedestrians, which substantially reduces the number of such trips and increases the number of traffic injuries and fatalities.

It is exceptionally improper to install what amounts to a highway “deceleration” lane in a city (not to mention the fact that it would further widen an already over-wide roadway). Cities should not have deceleration lanes, overpasses, flyovers, grade separations, highway interchanges, 6- or 8- or 10-lane configurations or anything else that accommodates highway speeds by motor vehicles and undermines the important need to create lower-speed, human-scaled dimensions in our infrastructure.

It is likely that this proposal is a response to historical rear-end collisions in that location, where cars following too close behind cars in front of them rear-end the car ahead when the car ahead makes a right turn onto Raleigh. But this “solution” simply enables a form of travel (inattentive, high-speed driving and tailgating) that is inappropriate in a city.

Despite what conventional traffic engineers believe, roadway design influences travel behavior positively or negatively. When Boulder builds highway-oriented design, it inevitably induces an increase in inappropriate highway-style (read: high-speed, inattentive) driving. This is toxic for a city. Street design needs to induce desirable behavior, not induce undesirable behavior.

Shame on Boulder for this proposal.

I have to wonder how much money the City will spend to worsen its transportation system in this way?

 

 

 

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Filed under Bicycling, Economics, Sprawl, Suburbia, Transportation, Urban Design, Walking

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