We have been making the trip from Shreveport for years. On the drive, let me give you this advice, on the way down, we like to go I-20 through Jackson, then down through Hattiesburg, Mobile, etc. On the way back, however, we stay on I-10 to Baton Rouge (our tradition is to eat lunch at Georges, an LSU joint), then head back north on I-49. The drive on I-49 is so easy, virtually no traffic.
BUT! Do you hop off I-10 at Port Allen to take 190 to I-49 or take I-10 the whole way from BR to Lafayette? HWY 190 is actually quicker as you hit 49 at Opelousas. You also avoid the God forsaken elevated Atchafalaya Spillway Death Race! Used to dig fried anything po-boys and cheese fries at Georges. Yum.