The centroid near Dayton is particularly important because it is closest to the population center of the US and Canada. Dayton is within 500 miles of 60% of the US population and manufacturing capacity, as well as 60% of Canada's population. The region includes the interchange between I-70 and I-75, one of the busiest in the nation, with 154,000 vehicles passing through per day, of which 30–35% are trucks hauling goods. In addition, the I-75 corridor is home to the busiest north-south rail route east of the Mississippi River.