In the January 23, 1974, issue of the Mandeville Banner, a monorail system had just been proposed for service between Covington and Slidell. Click on the image below for details.
The monorail project probably would have been given the go-ahead, from St. Tammany to Slidell, Baton Rouge, and maybe even New Orleans, if a proposed international jetport would have been built in the middle of St. Tammany.
Later in 1974, developers were eyeing the vast acreage of central St. Tammany as the perfect place to locate the regional airport that would have served the Crescent City, Baton Rouge and the Mississippi Gulf Coast all at the same time. Those areas decided to keep their international airports closer to home, however, so a monorail to and from the airport was not necessary.
Over the years, another proposed monorail system would include one running in-between the two spans of the Lake Pontchartrain Causeway.