Yeah, its true. I spend a lot of time on the road and know this is the law in most states. Fines vary by states and some states like WY (IIRC) have signs posted.
Maximum moving violation in Louisiana is around $185 which includes court costs and the fine itself. Add some more for a bench warrant if you can’t pay it. The only way you could get up to $745 here is if you had multiple violations such as passing on the right + speeding + failure to yield to emergency vehicle + brake light out.