The pie charts illustrate the means of transportation changes employed by working women in the wide range of cities in the USA between the years of 1999 and 2009.
Overall, in the year of 1990, the metro was the most used vehicle, while the car sharing mode made the lowest contribution. In comparison, in 2009, the metro, although decreasing, still dominated the percentage; meanwhile, the sort of car sharing was still the least significant of carriage despite its double rise in the year before. Besides, the train remained stable through years.
In 1990, A way of walking to work by females in the United States accounted for 14 percent, and it rose to 17 percent. The car sharing and bicycle modes, in 1990, made up only 2% and 6% respectively, but in 2009, the percentages of two transport means double-increased to 4 and 11 percent consecutively, though they were still the least important vehicles.
On the contrary, in 1990, the proportion of metro transport was 22%, the most important transport, and it experienced a 2-percent decrease in 2009. The bus initially contributed to 21%; then, it declined to 16% in the year 2009. Also, the kind of private car used to work shrunk to 15%. In the meantime, the rate of railway transportation did not change between the two years.