State Route 20 (SR 20) is a state highway in the northern part of the U.S. state of Alabama. It travels from the Tennessee state line, where it continues as Tennessee State Route 69, northwest of Florence, east to Interstate 65 (I-65), east of Decatur. It crosses the Tennessee River at Florence (with US 43, US 72, SR 17, and SR 157) and also at Decatur (with US 31 and US 72 Alt.) US 72 Alt. follows SR 20 from the intersection with US 72 at Muscle Shoals to I-65 east of Decatur, the entire stretch being four-laned. Route description SR 20 begins in Waterloo at the Tennessee state line. It junctions with the Natchez Trace Parkway and enters Florence. In Florence, the route junctions with SR 133. It continues south to parallel the Tennessee River, heading east for just a mile as Coffee Road before junctioning with US 72 and US 43 at a Parclo. It crosses the Tennessee River with the two routes, SR 17, and SR 13. This is a quintuple concurrency. The routes enter Colbert County and Tuscumbia. The routes junction with SR 184. They pass by a few restaurants and a Planet Pepsi building near this junction. The routes reach Muscle Shoals. Here, US 43/SR 17/SR 13 and US 72 turn to the south and west respectively, while SR 20 turns east with U.S. 72 Alt. The two routes junction with SR 133 again and SR 157. This is the southern terminus of SR 133 and the continuation of SR 157. The two routes split off at Leighton. SR 157 continues south to Moulton and Cullman along the right-of-way. US 72 Alt. and SR 20 turn to the direct east/west and eventually enter Lawrence County. The routes enter Town Creek and junction with AL-101. The routes continue to Courtland and then junction with SR 33. This stretch of road is mostly flat. The routes continue east to the Morgan County line and enter Trinity. The stretch between here and SR 67 is well-known for containing multiple industrial plants, such as 3M and Nucor. The routes junction with SR 67 and gain the Corridor V name. The routes pass through Decatur, junctioning with US 31. This junction is limited because there is no direct connection between US 31 north and SR 20 west. Traffic making that connection must use a short side road onto a short