January 3, 2011 report
Have we reached peak travel?
The studys authors, Lee Schipper of the University of California, Berkeley, and Stanford University and Adam Millard-Ball, a doctoral candidate at Stanford University, analyzed travel trends from the US, the UK, Canada, Sweden, France, Germany, Japan, and Australia from 1970 through 2008. For each country, they plotted the distance traveled per capita per year by car, pickup truck, bus, plane, train, light rail, streetcar, and subway, and compared it to the countrys gross domestic product per capita.
They found a correlation between rising prosperity and passenger travel from 1970 to 2003, after which passenger travel stopped growing (while GDP per capita continued to rise). At this peak travel period, GDP per capita was $37,000 in the US and between $25,000 and $30,000 in the other seven countries. During the past few years, motorized travel in the US has plateaued at around 26,000 km/year per person, 10,000 km/year per person in Japan, and between 13,000 and 17,000 km/year per person in the other six countries. (See above graph.)
Since 2003, motorized travel demand has leveled out or even declined in most of the countries studied, and travel in private vehicles has declined, the authors wrote in their study. Car ownership has continued to rise, but these cars are being driven less.
The researchers speculated that several factors have contributed to the apparent peak in passenger travel. One factor is saturation in vehicle ownership: in the US, there are about 700 cars per 1,000 people (which is more cars than licensed drivers), and about 500 cars per 1,000 people in most of the other countries. Basically, everyone who wants to drive, drives. Since 2007, car ownership in the US has declined due to the recession. Another limiting factor is time: people already spend an average of 1.1 hours per day traveling, and speed limits for the large part remain fixed. Other factors include high gas prices and an aging population that doesnt commute.
The researchers think that the biggest factor of the travel plateau may be traffic congestion. As Schipper said in an interview with Miller-McCune, My basic thesis is, 'There aint room on the road.' You cant move in Jakarta or Bangkok or any large city in Latin America or in any city in the wealthy part of China. I think Manila takes the prize. Yes, fuel economy is really important, and yes, hybrid cars will help. But even a car that generates no CO2 still generates a traffic problem. Sadly, what is going to restrain car use the most is that you cant move.
Perhaps the biggest advantage of peak travel is that, if passenger travel continues to stay the same while vehicles become more fuel-efficient, then reducing transportation emissions may not be as daunting as previously thought. Today, the average American car uses a third less fuel per mile than in 1973, despite consumer demand for larger vehicles.
Although the researchers note that their results are not conclusive and further research is needed, they conclude that the assumption that travel demand will continue to rise should be treated with caution.
via: Miller-McCune and TreeHugger
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