5 ms·

Those pictures where they show car, bus, and bicycle density side by side really drive this point home: http://www.3fidi.com/wp-content/uploads/2012/11/60_peop

by ufo 8y ago

Those pictures where they show car, bus, and bicycle density side by side really drive this point home: http://www.3fidi.com/wp-content/uploads/2012/11/60_people_bikes_cars_1_bus_greece.jpg http://www.3fidi.com/wp-content/uploads/2012/11/60_people_bi... http://www.citymetric.com/sites/default/files/images/car%20bike.jpg http://www.citymetric.com/sites/default/files/images/car%20b... And rail mass transit is even denser!

brianwawok 8y ago
That picture doesn't make sense, because cars don't drive that close together, nor do bikes ride that close together. Show 60 cars at 45 mph vs 60 bikers at 15 mph for a better density view.
- a_imho 8y ago
  nor do bikes ride that close together In my experiece they absolutely do, but it is rare to see a big pack together.
- throwaway76543 8y ago
  You'll also want to take into account the 300% increase in speed. Transportation isn't about static density it's about throughput. Objects moving 3x faster can be 1/3 as dense and have the same overall throughput.
  - jcranmer 8y ago
    Higher speed actually translates into less throughput. Cars take up more than just their physical space; there is also a gap that is needed to stop safely in time--and this gap grows according to the square of velocity. (You can argue that people don't usually leave sufficient space to stop, but I will point out that self-driving cars, which prompted this discussion, are going to be following those basic safety rules)
    - throwaway76543 8y ago
      No, higher speed always results in higher throughput given the same density. Your complaint is that cars lower density as speed increases, which is true, but you're still looking at this too narrowly. Consider the bus.
- mcguire 8y ago
  "...nor do bikes ride that close together." https://bicycledutch.files.wordpress.com/2013/03/amsterdam.jpg https://bicycledutch.files.wordpress.com/2013/03/amsterdam.j...
  - brianwawok 8y ago
    I have ridden for years in the US, and you do not get that proximity of bikers outside of a peloton.
    - bradlys 8y ago
      It's also not in the US. You don't see that number of commuting bikers anywhere in the US. That's not the point though.
- ufo 8y ago
  The minimum breaking distance between cars grows quadratically with speed. When roads are saturated they have higher thoughtput at lower speeds.
Bromskloss 8y ago
Even denser: people packed into a container. The point is that these comparisons leave out all but one aspect.
IshKebab 8y ago
Every one of those comparisons I've seen is deceptive - e.g. in this one they have a full bus, but one person per car.
- Tyrek 8y ago
  Is it that unrealistic? During rush hour, most buses I've seen are packed, whereas most cars on the road are not carpools.
  - RobertoG 8y ago
    and not only that, but buses are almost continually working but most cars spend most of the day parked taking up some public space.

by ufo 8y ago

brianwawok 8y ago

That picture doesn't make sense, because cars don't drive that close together, nor do bikes ride that close together. Show 60 cars at 45 mph vs 60 bikers at 15 mph for a better density view.

a_imho 8y ago
nor do bikes ride that close together In my experiece they absolutely do, but it is rare to see a big pack together.
throwaway76543 8y ago
You'll also want to take into account the 300% increase in speed. Transportation isn't about static density it's about throughput. Objects moving 3x faster can be 1/3 as dense and have the same overall throughput.
- jcranmer 8y ago
  Higher speed actually translates into less throughput. Cars take up more than just their physical space; there is also a gap that is needed to stop safely in time--and this gap grows according to the square of velocity. (You can argue that people don't usually leave sufficient space to stop, but I will point out that self-driving cars, which prompted this discussion, are going to be following those basic safety rules)
  - throwaway76543 8y ago
    No, higher speed always results in higher throughput given the same density. Your complaint is that cars lower density as speed increases, which is true, but you're still looking at this too narrowly. Consider the bus.
mcguire 8y ago
"...nor do bikes ride that close together." https://bicycledutch.files.wordpress.com/2013/03/amsterdam.jpg https://bicycledutch.files.wordpress.com/2013/03/amsterdam.j...
- brianwawok 8y ago
  I have ridden for years in the US, and you do not get that proximity of bikers outside of a peloton.
  - bradlys 8y ago
    It's also not in the US. You don't see that number of commuting bikers anywhere in the US. That's not the point though.
ufo 8y ago
The minimum breaking distance between cars grows quadratically with speed. When roads are saturated they have higher thoughtput at lower speeds.

Bromskloss 8y ago

Even denser: people packed into a container. The point is that these comparisons leave out all but one aspect.

IshKebab 8y ago

Every one of those comparisons I've seen is deceptive - e.g. in this one they have a full bus, but one person per car.

Tyrek 8y ago
Is it that unrealistic? During rush hour, most buses I've seen are packed, whereas most cars on the road are not carpools.
- RobertoG 8y ago
  and not only that, but buses are almost continually working but most cars spend most of the day parked taking up some public space.