The speed limits on the Lake Pontchartrain Causeway are strictly enforced. There is also some confusion on what exactly the speed limit on the Southbound span is. The Southbound span has a day speed limit of 65 and a night speed limit of 55. The views of what constitutes day from night is up to the Causeway Police Officer. The bridge has its very own police department. They are extremely strict. I’ve gotten a ticket for going 65 Southbound when I thought it was day, and the officer said it was night. I’ve also gotten a ticket for driving 67 in a 65 going northbound. The major traps are at the "crossovers". There is also the now-unused 9 mile crossover on the Southbound span that always has a Causeway Police Officer in it. If you’re on it, do not speed. You will get a ticket. If you’re driving Southbound, and you’re not sure if it’s day or night, it’s night.