A primary goal of bicycle-sharing systems has been to reduce traffic congestion, particularly in large urban areas. Some empirical evidence indicates that this goal has been achieved to varying degrees in different cities. A 2015 article in "Transport Reviews" examined bike-share systems in five cities, including Washington, D.C. and Minneapolis. The article found that in D.C., individuals substituted bike-share rides for automobile trips 8 percent of the time, and almost 20 percent of the time in Minneapolis. A separate study on Washington, D.C.'s Capital Bikeshare found that the bike-share program contributed a 2 to 3 percent reduction in traffic congestion within the evaluated neighborhood. 2017 studies in Beijing and Shanghai have linked the massive increase of dockless bike shares to the decrease in the number of private automobile trips that are less than five kilometres. In Guangzhou, the arrival of dockless bike shares had a positive impact in the growth of cycling modeshare.