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Traffic engineering: convenience vs. consumption

  1. Jul 10, 2008 #1
    Is the current traffic patterning based on maximizing convenience rather than minimizing fuel consumption? If there is a difference, how can we change traffic engineering to save gas, and how much might we save in the near future?
     
  2. jcsd
  3. Jul 10, 2008 #2

    NoTime

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    Neither, It's optimized for control.
    Bad for gas and convenience.
     
  4. Jul 11, 2008 #3

    stewartcs

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    This is just my rambling but I believe the traffic problems are a result of too many on and off ramps. In the US they are typically every 1 mile apart in most areas. This leads to entirely too much congestion in the merging areas which propagates throughout the flow.

    If instead the highways were used and built as intended (i.e. for long distance travel and not soccer moms taking their kids to school 3 miles down the road - no offense to soccer moms) then traffic flow would be improved and fuel savings would increase due to less stop and go.

    Just my 2 cents.

    CS
     
  5. Jul 11, 2008 #4

    Mech_Engineer

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    Maximizing in-city mileage means minimizing the number of stops a vehicle has to take getting to its destination. Each time a vehicle stops it scrubs off all of its kinetic energy, so more gasoline must be burned to bring the vehicle back up to speed.

    It seems to me that traffic patterns are normally timed to allow cars to follow a path of green lights (although in practice it seems that this is a rare occurence), so in that way the number of stops for any vehicle following that path is minimized, and therefore it would seem that gas consumption for that vehicle is also minimized.
     
    Last edited: Jul 11, 2008
  6. Jul 11, 2008 #5

    Mech_Engineer

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    When compared to the alternative, I usually much prefer inner-city highways if i have to go 5 to 10 miles in a larger city, mainly because you can usually average a much higher speed (around 50-60mph), and avoid stop-and-go congestion that is caused by stoplights every quarter to half mile.
     
  7. Jul 11, 2008 #6
    most of the local effort is in so called traffic calming
    this very very misguided idea is backed by NIMBY's
    who just do not want ''OUTSIDERS" to use the public right of ways
    and aimed at slowing traffic flow by various evil plans
    most inc extra stops inc 3 or 4 way stops EVERYWHERE
    or slowing gimmicks like speed bumps
    traffic circles ,
    and new laws like no turns inc right turns at certain times of day
    one way streets [to prevent use]
    and flat out closing streets with barricades

    the whole idea is to limit traffic flow on back streets
    and to force the traffic on to major roads
    and not allow sheet flow on back streets
    BUT THE MAJORS ARE ALREADY SO OVER CROWDED it creates GRIDLOCK
    and as a backstreet runner I HATE IT

    as before this evil idea I could cut out of the GRIDLOCK
    by getting off the creeping major roads and useing the back streets
    and save about 1/2 the time it takes to move across this city at rush hour
    AND IN THE CURRENT GAS PRICE SPIKE COSTING BILLIONS
    in wasted fuel thanks to the NIMBYs
     
    Last edited: Jul 11, 2008
  8. Jul 11, 2008 #7
    I agree.

    Recently, they added "express lanes" on our interstate highway. These two lanes occupy the far left, and are separated by cones. Motorists enter near downtown, and may not exit for about 10 miles. They did this because a high percentage of people who work in the city are from the county north of us. By segregating traffic people can't merge across four lanes, and long-range travelers are not bothered by the on-ramps every half mile.

    Of course since it's a new system, we've already had SUV rollovers, barricades ran over, and cars smashed. And this was the first day of testing.
     
  9. Jul 12, 2008 #8

    LURCH

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    But this only works with one-way streets. It is impossible (at least in any practicle sense) to time the lights on a two-way street. I spent a year living in Fort Wayne Indiana, and all of the streets in town are one-way and the lights are timed. Driving through town was really efficient; once you hit a green light, you had green all the way through town, or untill somebody in front of you hit their breaks to turn. If you left enough space between yourself and the guy ahead of you, you never needed to touch your breaks all the way through town.

    But to set up this type of traffic flow requires planning the whole thing out before you start building the town. Unfortunately, most towns start as a few buildings with roadways going straight from one to another, then more buildings get added, and more roads to connect them, all in a fairly random fashion. So, in response to your original question, I would say that the traffic flow is not planned for convenience or fuel economy, because it is mostly not "planned" at all.
     
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