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How much of the "road cost" can be eliminated by reducing car usage by 90% in cities? I'm pretty sure that buses, delivery trucks, ambulances, and police cars

by anamax 15y ago

How much of the "road cost" can be eliminated by reducing car usage by 90% in cities? I'm pretty sure that buses, delivery trucks, ambulances, and police cars need roads, so a significant fraction of the road cost (in cities) is required even if there isn't a single private passenger car.

saalweachter 15y ago
Eliminating extra traffic reduces the amount of wear-and-tear on a street, which means you can go more years without resurfacing or replacing it. So even if you still need all of the roads, they could still cost significantly less to maintain. That said, I'm not really sure how the math works: delivery trucks and buses are a smaller number of the vehicles on the road, but they also weigh a lot more than cars. Some DOT probably has a chart somewhere which breaks down road wear by vehicle type.
- anamax 15y ago
  > Eliminating extra traffic reduces the amount of wear-and-tear on a street, which means you can go more years without resurfacing or replacing it. The standard argument is that wear goes up either exponentially (which seems wrong) or quadratically (seems more reasonable) with vehicle weight. Since heavy vehicle use will actually go up (more delivery) if we eliminate cars.... I've seen how other activities, tearing up streets for utilities and the like, which are surprisingly common in cities, lead to street repair. Those activities won't change if cars are eliminated. Parking garages will go away, and major streets could be narrower. I doubt that either effect is significant compared to the road costs which have been claimed to be huge.
  - saalweachter 15y ago
    The formula I found was quartic, from [1] Nref = Nx (Wx / Wref)^4 Nref = number of trips of reference vehicle Nx = number of trips of other vehicle Wref = weight of reference vehicle Wx = weight of other vehicle The quartic formula really works in our favor for bicycle commuting: if a bicycle (with rider) is 1/20th the weight of a car, the bicycle will produce 0.000625% the wear of the car. So if commuting were the only purpose of the road, you would essentially never need to replace a road again. This does make adding (larger) delivery vehicles quite bad. If the average delivery vehicle is twice as heavy as the average passenger car which was formerly used, each trip will produce 16 times as much wear. Looking up the curb weights for a Chevy cargo van (5000 lb) and a Toyota Corolla (2800 lb), the actual wear factor is 10x. [1] http://www.nvfnorden.org/lisalib/getfile.aspx?itemid=601 http://www.nvfnorden.org/lisalib/getfile.aspx?itemid=601
    - anamax 15y ago
      > So if [bike] commuting were the only purpose of the road, you would essentially never need to replace a road again. You're assuming that use is the only thing that harms roads, and that's clearly wrong. I mentioned tearing up the roads for utility changes. Another factor is weather, which amplifies the problems caused by utility "tear ups". It's fairly easy to see these effects; pedestrian-only and bike-and-pedestrian-only "roads" deteriorate. However, we know also know that (as you mentioned), these roads won't be bike only. In short, there will be some maintenance savings, but not a lot.

by anamax 15y ago

saalweachter 15y ago

Eliminating extra traffic reduces the amount of wear-and-tear on a street, which means you can go more years without resurfacing or replacing it. So even if you still need all of the roads, they could still cost significantly less to maintain. That said, I'm not really sure how the math works: delivery trucks and buses are a smaller number of the vehicles on the road, but they also weigh a lot more than cars. Some DOT probably has a chart somewhere which breaks down road wear by vehicle type.

anamax 15y ago
> Eliminating extra traffic reduces the amount of wear-and-tear on a street, which means you can go more years without resurfacing or replacing it. The standard argument is that wear goes up either exponentially (which seems wrong) or quadratically (seems more reasonable) with vehicle weight. Since heavy vehicle use will actually go up (more delivery) if we eliminate cars.... I've seen how other activities, tearing up streets for utilities and the like, which are surprisingly common in cities, lead to street repair. Those activities won't change if cars are eliminated. Parking garages will go away, and major streets could be narrower. I doubt that either effect is significant compared to the road costs which have been claimed to be huge.
- saalweachter 15y ago
  The formula I found was quartic, from [1] Nref = Nx (Wx / Wref)^4 Nref = number of trips of reference vehicle Nx = number of trips of other vehicle Wref = weight of reference vehicle Wx = weight of other vehicle The quartic formula really works in our favor for bicycle commuting: if a bicycle (with rider) is 1/20th the weight of a car, the bicycle will produce 0.000625% the wear of the car. So if commuting were the only purpose of the road, you would essentially never need to replace a road again. This does make adding (larger) delivery vehicles quite bad. If the average delivery vehicle is twice as heavy as the average passenger car which was formerly used, each trip will produce 16 times as much wear. Looking up the curb weights for a Chevy cargo van (5000 lb) and a Toyota Corolla (2800 lb), the actual wear factor is 10x. [1] http://www.nvfnorden.org/lisalib/getfile.aspx?itemid=601 http://www.nvfnorden.org/lisalib/getfile.aspx?itemid=601
  - anamax 15y ago
    > So if [bike] commuting were the only purpose of the road, you would essentially never need to replace a road again. You're assuming that use is the only thing that harms roads, and that's clearly wrong. I mentioned tearing up the roads for utility changes. Another factor is weather, which amplifies the problems caused by utility "tear ups". It's fairly easy to see these effects; pedestrian-only and bike-and-pedestrian-only "roads" deteriorate. However, we know also know that (as you mentioned), these roads won't be bike only. In short, there will be some maintenance savings, but not a lot.