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  bycycle

  Guinness74 - Luckily, there are a few utopian areas for bikes. Portland for example, has it's own mapping system here: http://bycycle.org/
  It gives directions based either on normal (quickest) or safer (less traffic) routes. I believe it basically overlays Portland's bike map with Google mapping to figure out which ways are best for bikes.
  On Google Maps adds walking directions posted 1 year, 4 months ago 4 Responses

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  Re: Co2 comparison articles

  Tarl,
  Done: 2008 BMW M5, mid-size, 17mpg highway. One of many new cars still with that bad a rating.
  $5 please.

  For the car: 1US gal gas = ~20lb CO2 emitted
  So at 25mpg (a conservative number we now see) that's 240lbs CO2 = 108kg CO2 per car. So pretty close to the 104 kg CO2 per car stated above for a 300 mile trip.
  If we took the ole' BMW at 17mpg, we're up to almost 350 lbs CO2 for the same trip per person. So we're up to 35,000 lbs CO2 for 100 BMW's.

  For a plane, I agree, it's hard to break it down by person and expect that there is a linear relationship between the CO2 emitted and number of people. 1 passenger flying from Boston to Philly will technically emit more than 100 passengers flying as the flight will have taken place either way. (same as bus and train theory) It's essentially plane-pooling right?

  Boeing states that the average 747 burns 5 gallons of fuel per mile. I'm sure this is a low-ball estimate as it doesn't take into account take-off and taxiing and all that. But whatever, for simplicity a 300 mile trip would equal 1500 gallons burned. Assuming jet fuel emits 21 lbs of CO2 per gallon, that's 31,500 lbs CO2 flat out.

  So which is more environmental? Probably the train and carpooling. And at least they still have food to offer unlike the airlines.

  Wanna get more detailed? Check out this paper for more info on the variables used in calculating per person CO2 emissions on planes:

  http://www.carbonplanet.com/downloads/Flight_Calculator_I ...
  On Umbra on driving versus flying posted 1 year, 4 months ago 10 Responses