Transportation plays an important role in the character of the Mill Creek Watershed, affecting the land use, commerce, and public health of the region. From an infrastructure perspective, the watershed contains (NUMBER AND SOURCE NEED) linear miles of roads, (NUMBER) railways, as well as sidewalks, bike paths and greenways. These highways include Interstates I-75, I-71, I-74, and I-275, all of which pass through the watershed. Respectively located to the north and south of the watershed, Dayton International Airport and Greater Cincinnati/Northern Kentucky International Airport offer another transportation option. The region's four highways and numerous state, county, and local roads support a growing number of roads. commuters. According to the 2008 OKI 2030 Regional Transportation Plan, 398,465 Hamilton County residents commuted to work in 2000; 15.6 percent of these residents traveled outside of Hamilton County for these purposes. This percentage has increased since the 1970s, when only 10.1 percent of commuters left the county. Butler County ha...