Amtrak - This webpage provides information regarding train travel, particularly in the Southern United States. Note that not all cities have a station but may be served by a nearby area.
Bureau of Transportation Statistics - This webpage provides access to various statistics related to transportation. Covered topics include safety, passenger travel, and looks at different modes of transportation (i.e. air, freight). Data coverage varies, but can usually be found at the national and state level.
Highway Statistics - This resource from the Federal Highway Administration features statistics regarding highways and motor vehicle travel, such as number of vehicle registrations and number of licensed drivers by state. Data is presented at the national and state level.
Railroads and States (AAR) - This webpage from the Association of American Railroads provides statistics regarding railroads in Louisiana. Note that the data is at the state level.
Traffic Safety Facts - This resource from the National Highway Traffic Safety Administration provides statistics regarding traffic, such as the number of fatalities from accidents, at the national and state level. Some data is available at the parish level.