"Dear Snowstone: WHY."

This specific Casindus Havelle variant is operated by the SNC's Traffic Division as part of a rapid response force to combat enemies entering Snowstone by land... or just some gangsters doing some illegal street races.
It is armed with a 150mm AA cannon sourced from vessels shot by the SNC in past conflicts, though constables will tell you that cannon is more suited for fighting ground targets. When part of a rapid response force, the Havelle is tasked with providing fire support for pursuit vehicles and motorcycles, holding the enemy off until more specialised vehicles can enter the battlefield.
Seating capacity: 12 or more if you're that ambitious.