Not Widening Roads Is Idiotic

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    Traffic in Hampton Roads in HORRENDOUS?  Have you tried driving through there in a.m., or p.m., rush hour?  Highways should have been widened years ago.

    And lets talk about the impact of hundreds of thousands of cars stuck in traffic:

    Wasting gas

    Emitting tons of CO2

    Lost economic output

    I get your point about “induced demand” but frankly, money would be better spent getting people into electric and other types of vehicles that emit fewer emissions and get better gas mileage.  There will never be the political will for “induced demand” so we need to come up with other ways to cut emissions and keep traffic moving in order to cut CO2 emissions.

    Oh and by the way, how is that “induced demand” working out in NOVA?  I assume you do not own a car, correct?

     

    • author of Walkable City: How Downtown Can Save America, One Step at a Time:

      Traffic studies are bullshit. They are bullshit for three main reasons:

      First: The computer model is only as good as its inputs, and there’s nothing easier than tweaking the inputs to get the outcome you want. When we were working in Oklahoma City, the local traffic engineer’s “Synchro” computer model said that our pro-pedestrian proposals would cause gridlock. So we borrowed that engineer’s computer model and handed it to our engineer, who tweaked the inputs, and voila: smooth sailing. By the way, the most commonly tweaked input is anticipated background growth, which typically needs tweaking anyway: most cities’ traffic models presume 1 to 2 percent annual growth, even when those cities are shrinking.

      Second: Traffic studies are typically performed by firms that do traffic engineering. This makes perfect sense-who else would do them? But guess who gets the big contract for the roadway expansion that the study deems necessary? As long as engineers are in charge of traffic studies, they will predict the need for engineering.

      Finally, and most essentially: The main problem with traffic studies is that they almost never consider the phenomenon of induced demand. Induced demand is the name for what happens when increasing the supply of roadways lowers the time cost of driving, causing more people to drive, and obliterating any reductions in congestion. We talked about this phenomenon at length in Suburban Nation twelve years ago, and the seminal text, The Elephant in the Bedroom: Automobile Dependency and Denial, was published by Hart and Spivak seven years prior. For this reason, I will not take the time here to address its causes, which are multifold and fascinating. Since these books were published, however, there have been additional reports, all essentially confirming what we knew then. In 2004, a meta-analysis of dozens of previous studies found that “on average, a 10 percent increase in lane miles induces an immediate 4 percent increase in vehicle miles traveled, which climbs to 10 percent-the entire new capacity-in a few years.

      […]

      Thanks to studies like this one, induced demand is by no means a professional secret. I was delighted to read the following recently, in Newsweek, hardly an esoteric publication: “demand from drivers tends to quickly overwhelm the new supply; today engineers acknowledge that building new roads usually makes traffic worse.

      […]

      Nobody likes congestion, and, despite appearances, I am not arguing here for more of it. Rather, I am asking that it be better understood by those who build and rebuild our communities, so that we can stop making stupid decisions that placate angry citizens while only hurting them in the long run. There is a simple answer to congestion-and it’s the only answer-which is to bring the costs of driving on crowded streets closer in line with its value. That technique is the subject of the Congestion Pricing section ahead.

    • BatCave

      “demand from drivers tends to quickly overwhelm the new supply; today engineers acknowledge that building new roads usually makes traffic worse.”

      Of course it does – because every year there are more cars and drivers on the road.  But it would be even worse, if the new roads weren’t built.  The numbers of vehicles does not stay static every year – it increases as do the number of drivers.  That is why we would be better off getting more electric vehicles on the road to offset the carbon emissions.    

      And this quote he had in his article is wrong:

      By the way, the most commonly tweaked input is anticipated background growth, which typically needs tweaking anyway: most cities’ traffic models presume 1 to 2 percent annual growth, even when those cities are shrinking.

      Cities are growing across this country because millenials want to live in them and are flooding into cities.  But the author of the article used a random city he was working in – Oklahoma City.  And maybe their growth has dropped – I could understand that.  Who would want to live there?