4 ms·

Now THAT is some cool engineering I can get behind.

0cf8612b2e1e 2y ago
That sounds like tens of millions in extra infrastructure costs so as to save trucks a tiny amount of gas. It is Texas, so anything is possible.
- sroussey 2y ago
  It’s Texas so you would assume they want people to waste gas.
  - Scoundreller 2y ago
    I thought they wanted to sell it to other states Never understood when major exporters of $thing would also specifically heavily subsidize $thing
    - TeMPOraL 2y ago
      Organic advertising? As in, showing prospective importers how cool it is to have abundance of $thing.
- dylan604 2y ago
  I've never heard of the proposed gravity assist theory in any discussion of these interchanges. Does it happen? Sure. Is it one of the reasons behind the design or just something that happens to also be true is the actual question. Pontificating on the interwebs is fun
  - tines 2y ago
    At https://www.fhwa.dot.gov/modiv/programs/intersta/docs/interchange_design_promptlist.pdf https://www.fhwa.dot.gov/modiv/programs/intersta/docs/interc... I see the short comment > At service interchanges it is desirable to design the interchanges with the crossroad above the freeway due to: > - The crossroad above the freeway results in longer sight distances to the exit ramp and gore area. > - The crossroad above the freeway allows gravity to assist the operation of both accelerating vehicles (the on-ramp has a down-grade) and decelerating vehicles (the off-ramp has an up-grade). In addition, the resulting grades generally provide longer sight distances. But that's the main thing I can find right now.
  - jnwatson 2y ago
    Energy savings isn't the point though. The point is so that large trucks won't slow down traffic having lost a bunch of energy from braking to get on a cloverleaf.
- TeMPOraL 2y ago
  Tens of millions in extra infrastructure costs to save a lot of trucks tiny amount of gas per ride, over many rides per year, over decades? That's literally what infrastructure is meant for.
  - deleted 2y ago
    [deleted]
- t-3 2y ago
  Infrastructure maintenance is far cheaper in areas without regular freeze/thaw cycles (like most of Texas). I wouldn't be surprised if almost all road spending in southern states went straight to highways and ignored local roads though, as there are a ton of dirt roads unless you are in a city or on the highway.

That sounds like tens of millions in extra infrastructure costs so as to save trucks a tiny amount of gas. It is Texas, so anything is possible.

sroussey 2y ago
It’s Texas so you would assume they want people to waste gas.
- Scoundreller 2y ago
  I thought they wanted to sell it to other states Never understood when major exporters of $thing would also specifically heavily subsidize $thing
  - TeMPOraL 2y ago
    Organic advertising? As in, showing prospective importers how cool it is to have abundance of $thing.
dylan604 2y ago
I've never heard of the proposed gravity assist theory in any discussion of these interchanges. Does it happen? Sure. Is it one of the reasons behind the design or just something that happens to also be true is the actual question. Pontificating on the interwebs is fun
- tines 2y ago
  At https://www.fhwa.dot.gov/modiv/programs/intersta/docs/interchange_design_promptlist.pdf https://www.fhwa.dot.gov/modiv/programs/intersta/docs/interc... I see the short comment > At service interchanges it is desirable to design the interchanges with the crossroad above the freeway due to: > - The crossroad above the freeway results in longer sight distances to the exit ramp and gore area. > - The crossroad above the freeway allows gravity to assist the operation of both accelerating vehicles (the on-ramp has a down-grade) and decelerating vehicles (the off-ramp has an up-grade). In addition, the resulting grades generally provide longer sight distances. But that's the main thing I can find right now.
- jnwatson 2y ago
  Energy savings isn't the point though. The point is so that large trucks won't slow down traffic having lost a bunch of energy from braking to get on a cloverleaf.
TeMPOraL 2y ago
Tens of millions in extra infrastructure costs to save a lot of trucks tiny amount of gas per ride, over many rides per year, over decades? That's literally what infrastructure is meant for.
- deleted 2y ago
  [deleted]
t-3 2y ago
Infrastructure maintenance is far cheaper in areas without regular freeze/thaw cycles (like most of Texas). I wouldn't be surprised if almost all road spending in southern states went straight to highways and ignored local roads though, as there are a ton of dirt roads unless you are in a city or on the highway.