Louisiana is not generally regarded as a haven of highway design innovation. That is slowly changing, with (for instance) the implementation of a continuous flow intersection in the wasteland suburbs of this very city. However, for the most part the reputation of design complacency is just deserved. Indeed, the state is plagued with a unillustrious residue of ancient urban freeways and arterials that compare poorly even to the antique parkways of the urban northeast.
But lo! hidden treasures abound which serve to belie this reputation. In north Baton Rouge, haven of many an odd roadway configuration, there exists an interesting interchange along the otherwise banal I-110:
A SPUI! Actually half a SPUI, but it functions in the same manner. This is the interchange of I-110 with Hollywood Street, the last exit on northbound before reaching the I-110/Airline Highway full stack. Due to the proximity of this massive interchange, only partial access is permitted at Hollywood: from NB I-110 to the surface street and from the surface street to SB I-110.
For some reason, these types of things always pop up in the most unassuming places here...