7 ms·

The only difference here that I think is really meaningful is that bike lanes generally aren't already fully built out and at full capacity. If we didn't belie

The only difference here that I think is really meaningful is that bike lanes generally aren't already fully built out and at full capacity. If we didn't believe bike lanes would induce demand for biking we wouldn't say "let's get people out of cars" as one of our major reasons for adding bike lanes. We accept - even hope! - from the start that more bike lanes will cause more biking. It has upsides compared to car commuting. But because we don't have an already saturated, congested network of bike lanes, we aren't going to be hitting the limits of "why didn't adding more parallel bike lanes reduce the amount of congestion?" - the congestion just doesn't exist, and we'd have to have a LOT more biking to make it exist. And if we get to that point, it's a big win! Fears of future bike traffic should not stop us from building bike lanes. Everything else about why "they're different" seems like handwaving.

danhor 5y ago
The point of the article is that bikes, by virtue of their limited speed, don't suffer the feedback loop of less density that cars do. The distance you can travel by bike in half an hour is not influenced that much by infrastructure.
- newsclues 5y ago
  Stop and go traffic is much slower than bike trails with minimal interruptions. Good bike infrastructure can make or break a commute in speed and safety
  - meristohm 5y ago
    My bicycle commute (and walking and running commute, depending on weather and mood) is one of the highlights of my day due in part to minimal waiting for other vehicles.
  - u801e 5y ago
    Separated rail or river trails are definitely a plus for bike commuting. But infrastructure parallel to roads with frequent intersections and mid-block driveways isn't really that much different than riding on the sidewalk (with all the hazards that come with it).
    - _jn 5y ago
      This may be true in suburban USA, but at least in European cities, sidewalks are used by pedestrians. You have to be alert riding a bike, but it’s a far cry from attempting to weave through foot traffic. The narrower roads also allow for quicker traffic light cycles, which is nicer than waiting a few minutes to cross your average suburban US arterial.
- gpm 5y ago
  One summer my commute by bicycle involved a route that regularly had a certain degree of bicycle congestion, enough that at one choke point in particular we were completely saturating the road (not just the bike lane, but the car lane heading in the right direction too). In that portion my speed was probably halved, congestion definitely does have an effect at high enough volumes. If more roads in the area had bike lanes this wouldn't have happened and my commute would have been faster (and more pleasant, riding in bicycle commuter traffic is somewhat stressful since everyone wants to go at different speeds). On the other hand if the same number of people were in cars in the same amount of space traffic would definitely have been much slower.
  - acomjean 5y ago
    I noticed on crowded bike days in the city it’s a little like being on a conveyor belt. You can try to ride a little faster but because of traffic lights and other riders there is just a speed you are going to be limited to. This is the same as driving.
  - donjoe 5y ago
    Would you have seen congestions if infrastructure built for cars (hint: traffic lights) wouldn't have existed?
    - gpm 5y ago
      I mean, no for two reasons. Traffic lights grouping people as you say, but also the bottle neck causing so people commuting on bikes to use this road wouldn't have existed if the other roads in the area were also designed to accommodate bikes. On the flip side, this isn't a city where a large percentage of people commuted by bike. If you turned all the people commuting by car and public transits into cyclists it wouldn't surprise me to find out there were still areas with congestion.
- u801e 5y ago
  Infrastructure tends to be constrained and will likely limit one's speed to the speed of the slowest cyclist ahead, since there's no room to pass. The other issue is that infrastructure doesn't take downgrades into account. So, while it can be safe to get up to speeds exceeding 20 mph (30 km/h) while in the center regular travel lane with a significant space cushion due to it's width, such speeds are hazardous with infrastructure. This means that with rolling terrain, the average speed will decrease significantly because one cannot safely travel at higher speeds on descents to make up for the time lost on ascents.
megameter 5y ago
A key analogy that went unused in the article is the Red Queen's Race: "it takes all the running you can do to stay in the same place" applies to car traffic precisely because cars are large and powerful and are persistently required to make slow turns and smooth stops relative to their size - think of all the roads where you have to carefully inch out, keep deliberate pace and stopping distance, and so on. Spaces that are "for cars" correlate to spaces that are unsafe "for people". If you add more than a small topping of car traffic to a road, they will impede each other. Therefore, to make large numbers of cars move quickly you have to add disproportionate amounts of car infrastructure, which creates car-centric land use patterns, which inhibits alternatives and makes cars the default by dint of being the smallest unit that can safely use a road. "If they get bigger, I must get bigger too" is applicable thinking for someone who wants to feel safe on the roads. If you reduce the scale, the speed, the headways, you have greater ability to adjust. While car pileups are expected, bicycle pileups are a thing usually only seen in races when the limits are being pushed. Ordinary bike commuters can navigate safely without rules when given a mixed bike/pedestrian space of sufficient size. Bikes don't get bigger to feel safer. The resulting infrastructure scales better for the cost, and the Red Queen's Race is averted. When bike lanes reach capacity, the failure mode is crowded-stadium, not stand-still freeway. Traffic slows down gradually instead of creating roadside bloodbaths. Transit does experience more of a headache from induced demand pressure since it also uses large vehicles, and the entire trip experience is contingent on not holding up that one train or bus - while Tokyo's system works, the crowding is notorious, and the train stations have sizable footprints. But as a collective effort, it can also be much more coordinated and deliver useful results from capacity increases.
dcposch 5y ago
Also, people lack intuition for just how much cars hog space. Here's 60 people in cars, in a bus, on bikes: https://lh3.ggpht.com/_9F9_RUESS2E/S7tbclwxiPI/AAAAAAAACmw/uI1bCpNuKNA/s800/picoftheday0012-space-60people.jpg https://lh3.ggpht.com/_9F9_RUESS2E/S7tbclwxiPI/AAAAAAAACmw/u... To quote ru paul... "you're not stuck in traffic. you are traffic."
- NickNameNick 5y ago
  I'm not a fan of that example - the cars photo is more zoomed in than the others.
  - deleted 5y ago
    [deleted]
  - chmod775 5y ago
    I mean... whatever: https://i.imgur.com/TVeeDBa.jpg https://i.imgur.com/TVeeDBa.jpg Those pictures are supposed to bring a point across, not be used for an accurate scientific measurement. Either way people will be aware not even three out of those 60 cars could drive in the space of that bus.
  - amrcnimgrnt 5y ago
    It also assumes the cars have one occupant. I rarely drive alone these days
    - wpm 5y ago
      Most average occupancy rates for private automobiles is less than 2, in the US I believe it’s about 1.3. Still not enough compared to how much space and how many resources they consume, let alone the externalities.
    - eloisius 5y ago
      It also doesn’t illustrate the real scale of space required to operate each vehicle. A car needs several car-lengths of space between them. Bikes can be operated more closely together. At speed all of these vehicles scale up to more space differently.
labster 5y ago
UC Davis alumnus here. Bike lanes at full capacity work much better than motor vehicle lanes at full capacity. You may have to wait to join the traffic, but since you need a smaller space there’s less wait time. Roundabouts are very efficient. Accidents do happen, but are far, far less deadly and can almost always be cleared in under two minutes. Just watch out for freshmen at the first rainstorm. You can tell them apart by their freshman stripe — the result of not having a rear fender.
thanatos519 5y ago
Don't add more parallel bike lanes. Put bike lanes on every street.

danhor 5y ago

The point of the article is that bikes, by virtue of their limited speed, don't suffer the feedback loop of less density that cars do. The distance you can travel by bike in half an hour is not influenced that much by infrastructure.

newsclues 5y ago
Stop and go traffic is much slower than bike trails with minimal interruptions. Good bike infrastructure can make or break a commute in speed and safety
- meristohm 5y ago
  My bicycle commute (and walking and running commute, depending on weather and mood) is one of the highlights of my day due in part to minimal waiting for other vehicles.
- u801e 5y ago
  Separated rail or river trails are definitely a plus for bike commuting. But infrastructure parallel to roads with frequent intersections and mid-block driveways isn't really that much different than riding on the sidewalk (with all the hazards that come with it).
  - _jn 5y ago
    This may be true in suburban USA, but at least in European cities, sidewalks are used by pedestrians. You have to be alert riding a bike, but it’s a far cry from attempting to weave through foot traffic. The narrower roads also allow for quicker traffic light cycles, which is nicer than waiting a few minutes to cross your average suburban US arterial.
gpm 5y ago
One summer my commute by bicycle involved a route that regularly had a certain degree of bicycle congestion, enough that at one choke point in particular we were completely saturating the road (not just the bike lane, but the car lane heading in the right direction too). In that portion my speed was probably halved, congestion definitely does have an effect at high enough volumes. If more roads in the area had bike lanes this wouldn't have happened and my commute would have been faster (and more pleasant, riding in bicycle commuter traffic is somewhat stressful since everyone wants to go at different speeds). On the other hand if the same number of people were in cars in the same amount of space traffic would definitely have been much slower.
- acomjean 5y ago
  I noticed on crowded bike days in the city it’s a little like being on a conveyor belt. You can try to ride a little faster but because of traffic lights and other riders there is just a speed you are going to be limited to. This is the same as driving.
- donjoe 5y ago
  Would you have seen congestions if infrastructure built for cars (hint: traffic lights) wouldn't have existed?
  - gpm 5y ago
    I mean, no for two reasons. Traffic lights grouping people as you say, but also the bottle neck causing so people commuting on bikes to use this road wouldn't have existed if the other roads in the area were also designed to accommodate bikes. On the flip side, this isn't a city where a large percentage of people commuted by bike. If you turned all the people commuting by car and public transits into cyclists it wouldn't surprise me to find out there were still areas with congestion.
u801e 5y ago
Infrastructure tends to be constrained and will likely limit one's speed to the speed of the slowest cyclist ahead, since there's no room to pass. The other issue is that infrastructure doesn't take downgrades into account. So, while it can be safe to get up to speeds exceeding 20 mph (30 km/h) while in the center regular travel lane with a significant space cushion due to it's width, such speeds are hazardous with infrastructure. This means that with rolling terrain, the average speed will decrease significantly because one cannot safely travel at higher speeds on descents to make up for the time lost on ascents.

megameter 5y ago

A key analogy that went unused in the article is the Red Queen's Race: "it takes all the running you can do to stay in the same place" applies to car traffic precisely because cars are large and powerful and are persistently required to make slow turns and smooth stops relative to their size - think of all the roads where you have to carefully inch out, keep deliberate pace and stopping distance, and so on. Spaces that are "for cars" correlate to spaces that are unsafe "for people". If you add more than a small topping of car traffic to a road, they will impede each other. Therefore, to make large numbers of cars move quickly you have to add disproportionate amounts of car infrastructure, which creates car-centric land use patterns, which inhibits alternatives and makes cars the default by dint of being the smallest unit that can safely use a road. "If they get bigger, I must get bigger too" is applicable thinking for someone who wants to feel safe on the roads. If you reduce the scale, the speed, the headways, you have greater ability to adjust. While car pileups are expected, bicycle pileups are a thing usually only seen in races when the limits are being pushed. Ordinary bike commuters can navigate safely without rules when given a mixed bike/pedestrian space of sufficient size. Bikes don't get bigger to feel safer. The resulting infrastructure scales better for the cost, and the Red Queen's Race is averted. When bike lanes reach capacity, the failure mode is crowded-stadium, not stand-still freeway. Traffic slows down gradually instead of creating roadside bloodbaths. Transit does experience more of a headache from induced demand pressure since it also uses large vehicles, and the entire trip experience is contingent on not holding up that one train or bus - while Tokyo's system works, the crowding is notorious, and the train stations have sizable footprints. But as a collective effort, it can also be much more coordinated and deliver useful results from capacity increases.

dcposch 5y ago

Also, people lack intuition for just how much cars hog space. Here's 60 people in cars, in a bus, on bikes: https://lh3.ggpht.com/_9F9_RUESS2E/S7tbclwxiPI/AAAAAAAACmw/uI1bCpNuKNA/s800/picoftheday0012-space-60people.jpg https://lh3.ggpht.com/_9F9_RUESS2E/S7tbclwxiPI/AAAAAAAACmw/u... To quote ru paul... "you're not stuck in traffic. you are traffic."

NickNameNick 5y ago
I'm not a fan of that example - the cars photo is more zoomed in than the others.
- deleted 5y ago
  [deleted]
- chmod775 5y ago
  I mean... whatever: https://i.imgur.com/TVeeDBa.jpg https://i.imgur.com/TVeeDBa.jpg Those pictures are supposed to bring a point across, not be used for an accurate scientific measurement. Either way people will be aware not even three out of those 60 cars could drive in the space of that bus.
- amrcnimgrnt 5y ago
  It also assumes the cars have one occupant. I rarely drive alone these days
  - wpm 5y ago
    Most average occupancy rates for private automobiles is less than 2, in the US I believe it’s about 1.3. Still not enough compared to how much space and how many resources they consume, let alone the externalities.
  - eloisius 5y ago
    It also doesn’t illustrate the real scale of space required to operate each vehicle. A car needs several car-lengths of space between them. Bikes can be operated more closely together. At speed all of these vehicles scale up to more space differently.

labster 5y ago

UC Davis alumnus here. Bike lanes at full capacity work much better than motor vehicle lanes at full capacity. You may have to wait to join the traffic, but since you need a smaller space there’s less wait time. Roundabouts are very efficient. Accidents do happen, but are far, far less deadly and can almost always be cleared in under two minutes. Just watch out for freshmen at the first rainstorm. You can tell them apart by their freshman stripe — the result of not having a rear fender.

thanatos519 5y ago

Don't add more parallel bike lanes. Put bike lanes on every street.