Baton Rouge public transportation is severely lacking. Most students avoid taking the city buses and cabs, and instead opt to pawn rides off of friends or stay in the campus area. The city system is in the process of revitalization efforts, but it will take major improvements for it to become a major mode of travel. However, the LSU bus system is fairly reliable and a good option for students (with patience) who want to travel in the campus area. The Greek bus transports both Greek and non-Greek students through campus during the day. The drunk bus is a great way to get from the bars to your late-night destination without having to designate a driver. Since LSU buses are free, there is no reason not to try them out.
Baton Rouge is fairly spread out, and since public transportation is far from reliable, the best bet is to try to come to LSU with a car. It is not a necessity and several students do survive without one, but it will give you the freedom to explore all of what Baton Rouge has to offer.