1970 to 2007.
The urban trip density in relation to population increased from
0.77 trips/person in 1970 to 2.29 trips/person in 2002, but decreased
to 1.86 trips/person in 2007. The increase in urban trips
overlaps with the population growth rates from 1970 to 1980, as
well as from 1980 to 2002 (Table 7 and Fig. 10). This result suggests
a mutual relationship between urban population growth and
transportation.
Interestingly, urban trip density—in comparison to residential
area expansion—drastically changed, declining from 0.015 trip/
m2 in 1970 to 0.009 trip/m2 in 1980. These figures reveal the