The My Wheels are Turning blog has another great article about urban design in Traverse City. That article reminds us of this Jane Jacobs quote.
Automobiles are often conveniently tagged as the villains responsible for the ills of cities and the disappointments and futilities of city planning. But the destructive effects of automobiles are much less a cause than a symptom of our incompetence at city building. The simple needs of automobiles are more easily understood and satisfied than the complex needs of cities, and a growing number of planners and designers have come to believe that if they can only solve the problems of traffic, they will thereby have solved the major problems of cities. Cities have much more intricate economic and social concerns than automobile traffic. How can you know what to try with traffic until you know how the city itself works, and what else it needs to do with its streets? You can’t.
— Jane Jacobs, Death and Life of Great American Cities
Bicycle advocates can find many examples to support Jacob’s quote. It’s relatively easy to define transportation problems in terms of motor vehicle levels of service (LOS) and average daily traffic (ADT). LOS and ADTs are easily measured and quantified for motor vehicles.
How do you measure real and perceived safety issues that create latent demand for non-motorized transportation options?
There’s also been recent discussion nationally about how congestion is measured in the U.S. This discussion was kicked off with the recent CEO for Cities report called, Driven Apart: How sprawl is lengthening our commutes and why misleading mobility measures are making things worse.
A new report from CEOs for Cities unveils the real reason Americans spend so much time in traffic and offers a dramatic critique of the 25 year old industry standard created by the Texas Transportation Institute’s Urban Mobility Report (UMR) – often used to justify billions of dollars in expenditures to build new roads and highways…
A close examination shows that the UMR has a number of major flaws that misstate and exaggerate the effects of congestion, particularly the Travel Time Index (TTI). TTI is the ratio of average peak hour travel times to average free flow travel times… Because this methodology does not take into account travel distances, it universally rewards cities that are spread out as opposed to compact urban areas.
It’s bottom line, common sense conclusion: “What creates traffic jams isn’t more cars and fewer highways, it’s sprawl.”
And Transportation for America published this article today which concurs.
The cycle is familiar by now. A study tells us what we all know: our roads are congested. We pour billions into new roads and lanes to “reduce congestion.” Then the study comes out two years later and just as before, our roads are still congested. There’s a call for new roads, new roads open up, we drive further and further, congestion goes up. Rinse and repeat.
That hypothetical study exists in Metro Detroit. It’s SEMCOG’s Congestion Management System Plan. It fails to mention sprawl as a possible cause for congestion (and never mentions increased bicycling as a partial solution.)
It does focus plenty on the LOS’s for motorists during peak travel time.
There is a bridge that carries I-96 traffic over the Huron Valley Trail just east of Milford Road. As part of a larger freeway construction project, MDOT wants to replace the bridge with a low maintenance box culvert. (The Huron Valley Trail currently passes under Kensington Road in a box culvert at Island Lake State Recreation Area.)
