From the south, LA 19 begins at an intersection with US 61 (Scenic Highway) north of downtown Baton Rouge. US 61 connects the city with St. Francisville and Natchez, Mississippi to the north. LA 19 laterals off of US 61 as it heads north on Scotland Avenue alongside the Canadian National Railway (CN) tracks through an area within the Baton Rouge city limits known as Scotlandville. Immediately after passing the local high school, LA 19 proceeds through a half diamond interchange with southbound I-110, which leads back to the downtown area. Here, the highway widens from a two-lane to an undivided four-lane highway. Just north of the interstate, the suburban surroundings abruptly change as LA 19 passes a series of small industrial facilities, including an ExxonMobil chemical plant. During this time, it intersects LA 423 (Thomas Road), a short connector to the parallel LA 67.