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You are missing that the cost of bike lanes isn't just in constructing and maintaining them. Adding bike lanes in cities means dropping car lanes because there'

You are missing that the cost of bike lanes isn't just in constructing and maintaining them. Adding bike lanes in cities means dropping car lanes because there's not enough space. That ends up creating potentially huge opportunity costs.

SilasX 7y ago
I wasn’t missing that, I just wasn’t addressing it; I was just addressing how to assess maintenance taxes. If there are other costs of having the road there, like its real estate usage, I agree that’s another factor to consider.
- read_if_gay_ 7y ago
  Okay. If we're just talking maintenance taxes then I agree the idea isn't nonsense. Excuse the misunderstanding.
Retric 7y ago
Bike lanes can handle more traffic per surface area than car lanes. Utilization is unfortunately low in most areas, but capacity wise it’s a clear net gain for city centers. Oddly enough, sidewalks are the most efficient use of space, but require good public transportation and extreme density to reach that threshold.
dragontamer 7y ago
Not quite IMO. Anyone who has done any amount of virtual traffic engineering (aka: Factorio, City Skylines, OpenTTD) knows that intersections are where the bottlenecks are. Its incredibly difficult to design a max-throughput intersection. Roads have a huge amount of throughput, most "traffic" just gets stuck at offramps and traffic lights. Narrowing a road to make room for bike lanes is a lower cost than people might think. If you're all going to get stuck at the next intersection anyway, it doesn't matter if you're a 2-lane, 4-lane, or 8-lane road.
- allovernow 7y ago
  > it doesn't matter if you're a 2-lane, 4-lane, or 8-lane road If you halve the capacity of the road, you're just going to spread the same cars (and congestion) among twice as many lights...and make traffic far worse.
  - Marsymars 7y ago
    Depends. My commute home from my office has a 6km of a three-lane road and then a single traffic light. The road never gets backed up more than a couple km from the traffic light, so even dropping it to a single lane wouldn't make any real difference to the throughput. The speed you drive on the three-lane road also makes no real difference to the throughput as long as you get the same amount of cars through the traffic light at each cycle.
    - pedrosorio 7y ago
      > as long as you get the same amount of cars through the traffic light at each cycle. Isn’t this proportional to the number of lanes in the road?
      - pmiller2 7y ago
        If all the lanes are used at capacity, yes. Otherwise, no.
      - Marsymars 7y ago
        The bit about speed prior to lights was meant to be separate from the bit about # of lanes. To clarify - I mean, e.g. that when there's 5km of free-flowing traffic before the lights, and then 1km of congestion, it doesn't matter how fast you drive for those 5km as long as it doesn't delay your passage through the lights. I could halve my speed from the speed limit for those 5km and still arrive at the congestion at the lights before it's my turn to go through them.
- pmiller2 7y ago
  It’s not all about throughput. Taking away car lanes in favor of bike lanes usually takes away parking as well. While that certainly has the desired effect of reducing car traffic to the area, it also increases the difficulty and expense of travel to the area. We’re seeing this in Oakland now, where they’re putting in bike lanes and taking away parking, while simultaneously doing nothing about the limited public transportation system. If you want to reduce vehicle traffic without seriously impacting the shops and restaurants in the area, you have to use both knobs available to increase people’s use of public transportation: make it harder and more expensive to drive a car, while also making it easier (and, preferably, cheaper as well) to take transit. One without the other is a disaster.
fpoling 7y ago
In Oslo, Norway the city builds a lot of bike lines . It narrowed streets for cars or removed parking places. I talked with a few folks with cars in the city and their typical response that it made them to get work faster with a car. Surely they have to walk more to a parking spot, but after that they drive faster through the city. Apparently street parking creates a lot of congestion.
jbay808 7y ago
There are opportunity costs in the other direction too.

SilasX 7y ago

I wasn’t missing that, I just wasn’t addressing it; I was just addressing how to assess maintenance taxes. If there are other costs of having the road there, like its real estate usage, I agree that’s another factor to consider.

read_if_gay_ 7y ago
Okay. If we're just talking maintenance taxes then I agree the idea isn't nonsense. Excuse the misunderstanding.

Retric 7y ago

Bike lanes can handle more traffic per surface area than car lanes. Utilization is unfortunately low in most areas, but capacity wise it’s a clear net gain for city centers. Oddly enough, sidewalks are the most efficient use of space, but require good public transportation and extreme density to reach that threshold.

dragontamer 7y ago

Not quite IMO. Anyone who has done any amount of virtual traffic engineering (aka: Factorio, City Skylines, OpenTTD) knows that intersections are where the bottlenecks are. Its incredibly difficult to design a max-throughput intersection. Roads have a huge amount of throughput, most "traffic" just gets stuck at offramps and traffic lights. Narrowing a road to make room for bike lanes is a lower cost than people might think. If you're all going to get stuck at the next intersection anyway, it doesn't matter if you're a 2-lane, 4-lane, or 8-lane road.

allovernow 7y ago
> it doesn't matter if you're a 2-lane, 4-lane, or 8-lane road If you halve the capacity of the road, you're just going to spread the same cars (and congestion) among twice as many lights...and make traffic far worse.
- Marsymars 7y ago
  Depends. My commute home from my office has a 6km of a three-lane road and then a single traffic light. The road never gets backed up more than a couple km from the traffic light, so even dropping it to a single lane wouldn't make any real difference to the throughput. The speed you drive on the three-lane road also makes no real difference to the throughput as long as you get the same amount of cars through the traffic light at each cycle.
  - pedrosorio 7y ago
    > as long as you get the same amount of cars through the traffic light at each cycle. Isn’t this proportional to the number of lanes in the road?
    - pmiller2 7y ago
      If all the lanes are used at capacity, yes. Otherwise, no.
    - Marsymars 7y ago
      The bit about speed prior to lights was meant to be separate from the bit about # of lanes. To clarify - I mean, e.g. that when there's 5km of free-flowing traffic before the lights, and then 1km of congestion, it doesn't matter how fast you drive for those 5km as long as it doesn't delay your passage through the lights. I could halve my speed from the speed limit for those 5km and still arrive at the congestion at the lights before it's my turn to go through them.
pmiller2 7y ago
It’s not all about throughput. Taking away car lanes in favor of bike lanes usually takes away parking as well. While that certainly has the desired effect of reducing car traffic to the area, it also increases the difficulty and expense of travel to the area. We’re seeing this in Oakland now, where they’re putting in bike lanes and taking away parking, while simultaneously doing nothing about the limited public transportation system. If you want to reduce vehicle traffic without seriously impacting the shops and restaurants in the area, you have to use both knobs available to increase people’s use of public transportation: make it harder and more expensive to drive a car, while also making it easier (and, preferably, cheaper as well) to take transit. One without the other is a disaster.

fpoling 7y ago

In Oslo, Norway the city builds a lot of bike lines . It narrowed streets for cars or removed parking places. I talked with a few folks with cars in the city and their typical response that it made them to get work faster with a car. Surely they have to walk more to a parking spot, but after that they drive faster through the city. Apparently street parking creates a lot of congestion.

jbay808 7y ago

There are opportunity costs in the other direction too.