Figure 2
Basic Variables of Human Mobility as Functions of Daily Distance Traveled
a: Travel Time
Travel time budget, h/cap/d
Daily distance traveled, km/cap/d
b: Travel Money Expenditure Shares
Travel money budget, percent disposable income
Daily distance traveled, km/cap/d
c: Trip Rate
Trip rate (cumulative), trips/cap/d
Daily distance traveled, km/cap/d
d: Trip Distance
Mean trip distance, km/trip
Daily distance traveled, km/cap/d
Empty circles in 2a = travel diary plus CATI
Dashed lines in 2a = ± 1 standard deviation
Note: The daily distances traveled in African villages were
estimated by multiplying the travel time budget by a mean walking
speed of four kilometers per hour. Those in Japan were derived from
Japan’s Statistic Bureau (1995) and multiplied by 0.86, the ratio
of the survey-based automobile travel distance to that reported by
official transit statistics. The data points in 2b slightly overestimate
travel money expenditure shares since the survey-based daily travel
distances often underestimate long distance travel (see table 2),
whereas the economic statistics-based travel money budget figures account for all travel.
Sources: Table 1 for travel time and components, OECD (various years), and U.S. Department of
Commerce (various years)
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