In downtown Baton Rouge, most speed limits are 30 mph. When you drive on residential streets in Baton Rouge, the speed limit is usually 45 mph. Interstates in and around Baton Rouge have a speed limit of 70 mph. Freeways coursing through Baton Rouge have a speed limit of 60 mph that increases to 75 mph as they move into more rural areas. Undivided roads have a speed limit of 55 mph, while divided highways have a speed limit of 65 mph.