Felix Salmon introduces Charles Komanoff’s work on the external cost of congestion in Manhattan:

Komanoff calculates (check out the “Value of Time” tab) that the average vehicle has 1.97 people in it, and that the average value of an hour of saved vehicle time south of 60th Street in Manhattan on a weekday is $48.89. Which means, basically, that driving a car into Manhattan on a weekday causes about $160 of negative externalities to everybody else.

Note that this cost is for congestion only and doesn’t consider pollution, public health, oil dependence, etc.

Of course, Seattle is far from a clone of Lower Manhattan, and you should be wary of studies that try to compute the monetary value of wasted time.  It’s not $160, but it’s not zero either, and people who claim their drive isn’t subsidized should recognize that.

Via Yglesias, who nationalizes the argument a bit:

If we implemented congestion pricing in those metropolitan areas suffering from chronic congestion and then gathered up all the revenue and lit it on fire, we would swiftly find ourselves living in a more prosperous society. And if we gathered up the revenue and did something else with it, we’d be even better off.

Also check out Komanoff’s report, “Subsidies for Traffic.” (pdf)

12 Replies to “The Cost of Congestion”

  1. Great post, Martin. People really can’t fathom how expensive auto dependence is. High quality transit is expensive. It’s extremely expensive, billions of dollars worth of expensive, but cars cost even more. People keep looking at the price tag of light rail and balking, but they never consider the unimaginably high cost of the alternative.

    One of the other significant externalities of driving is auto accidents. According to a study by the Urban Institute in 1994, auto accidents cost americans over $400 billion per year, which is likely over $500 billion in todays dollars. That is more than we spend on all U.S. military expenditures, not just Iraq, but all military everywhere combined. Tragically, auto insurance (one of the largest out of pocket costs for drivers) only covers 1/4 of the total cost of accidents. The remaining costs are completely uncompensated.

    Aaron Edlin, an economist at UC Berkely has done some excellent work on the “accident externality”. Logically, when you drive, you not only increase your own risk, but like congestion, you impose an increase in risk on everyone else by adding another moving target to the road that someone could run into.

    In a 2003 paper titled “The Accident Externality from Driving” available here, Edlin estimates that the typical driver imposes $2,500 in external accident costs per year in the state of California and that figure only counts the portion of accident costs covered by insurance.

    A couple more fun numbers: economists estimate that about 20% of GDP is spent on transportation, mostly cars, and that figure only includes direct expenditures including private expenditures on vehicle purchase, gas, maintenance and insurance and public expenditures on roads, but it does not include external costs like congestion, accidents, pollution, global climate change and it does not include parking (which is a lot more expensive than people think). If we take an extremely conservative estimate of those extra costs, we push the cost of cars to 25% of GDP. In reality is probably much higher.

    So here’s the perspective. The Gross Regional Product of the Puget Sound Metro Region (essentially the size of the entire metro economy) is about $200 billion per year (source). 25% of that is $50 billion per year, every year. And people say Sound Transit is expensive? At $500 million per year (source), total operating and capital budget combined, ST makes up 1% of what we spend on transportation in this region when you factor in not only public but private expenditures and externalities. If we were to build a transit system so good that 50% of our region could give up owning a car (i.e. what they’ve done in NYC), it would save our regional economy $25 billion per year, 50 times what we are spending on Sound Transit. One might say, “What a bargain.” One might also say, “Why the $%^& aren’t we spending more?!”

  2. There is a cost to congestion?

    Has Sound Transit added up all the hours of delays it will cause for all the thousands of vehicles per day the light rail trains will block at intersections? For example, at one major intersection in the Rainier Valley, about 22,000 vehicles per day cross the light rail tracks. The ST trains will block this cross traffic twice every 7.5 minutes during peak hours, when, presumably, cross traffic will also be heaviest. So how many passenger/hours of delays will the light rail cause at that one intersetion alone each day?

    What did the ST EIS calculate would be the total passenger hours of delays for vehciles at all intersections the light rail crosses along its route?

    1. Probably not, but then it didn’t calculate the added congestion associated with all those people being in cars, or in multiple buses, nor the time saved by people taking a train three times faster than a bus.

    2. The days of the primacy of the automobile over all other forms of transport are drawing to a close. New priorities are in the wind and the automobile (and its concomitant tremendously expensive petrol based economy) will be in decline after more than three quarters of a century of ascendance – to the long term benefit of us all.

    3. “Has Sound Transit added up all the hours of delays it will cause for all the thousands of vehicles per day the light rail trains will block at intersections?”

      Not “vehicles” but “people”! How many “people” are inconvenienced by the one person in a car blocking other cars, buses, streetcars, or light rail? So if the 200 people in a streetcar are blocking a couple of people in their cars, that is fine with me.

  3. A train three times faster than a bus? I have read that from downtown to the airport, the express bus is actually faster than the light rail is expected to be.

    I have also read that for some commuters from the Rainier Valley to where they want to go, the light rail will be slower than their current bus trip.

    Where did you get that figure?

    Lloyd: autos are becoming less and less dependent on petrol. Haven’t you heard?

    1. Taurus:

      Maybe slightly slower during ideal traffic conditions, but I tracked a 194 the other day at around 1pm. One was showing a two minute delay, the other was four minutes.

      The other big thing about Link is that it will serve more stops, more frequently than the 194 and have the capacity for much more people. Link benefits people going between more than just downtown and the airport.

      I’m sure some will have longer trips, but some people just don’t like change. I’m excited because Seattle is about to gain what so many other cities have. I had much more mobility living by Blue Line stations in Chicago than Seattle has ever had, My trip to the airport will be about a half-hour instead of an hour and my trip downtown will also be cut by about half.

      – Rob

    2. People think that electric cars will solve all our problems (including those created by the car itself!) but I don’t think so. This blog discussed the prospect of electric cars recently. Even if cars ran on something else, we’d still have the other problems associated with it.

      1. That and they may be burning less petrol, but cars today have much more plastic in them than a generation ago. Plastic=petrol; an electric car is still a car, consuming vast amounts of space and resources.

      2. There is also the matter of generating and distributing the electricity, or other means to power alternative fuel vehicles. No small matter, nor a small investment in infrastructure.

        And of course, continued reliance on cars, no matter what they run on, requires continued maintenance, replacement and expansion of our current auto infrastructure. Think roadways, bridges, stormwater detention and treatment facilities, etc.

        So even if we overcome the issues related to petrol dependent transportation, we as a society still also need to deal with funding the massive infrastructure required by cars. We can continue to provide solely for cars, or we can begin developing viable alternatives that lessen the demands and stresses placed on our auto infrastructure.

    3. On paper, yes, the bus headways are faster than the light rail is scheduled to be. Of course, as anyone who has actually ever ridden the 194 can tell you, when comparing what is on paper versus the reality of I5, the 194 would be faster only some of the time, performing worse at peak traffic volumes. Light rail will perform far more consistently from downtown to the airport.

      A couple of other items I would like to point out. First, the light rail is not intended to act solely as an airport shuttle, unlike the 194. It serves to move people through a multi-nodal transit corridor forming reliable and relatively quick connections between all points on the line. It is true that there will be many areas of the city that are not as conveniently served as the current bus system, but that is because you are comparing one train line to a full bus network. Light rail is not a panacea to all our transit woes. It is not intended to be as locally convenient as buses. Most cities rely on multiple intersecting train lines to provide quick links to very broad areas of the city (long haul trips) with buses and/or streetcars providing local access.

    4. The three times faster figure is a anecdotal case from the day I took the media ride. The point is that Link will generally be faster than the bus. In the Rainier Valley, that’s always the case unless the Link trip involves a transfer to a bus.

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