Jacksonville (and most of Florida) is extremely low lying with a high water table, so sub-surface construction (basements) and subways are basically impossible.

Jacksonville (and most of Florida) is extremely low lying with a high water table, so sub-surface construction (basements) and subways are basically impossible. Structurally, it's a low density, car-based city so light rail (as opposed to busses) requires a lot of up front investment without the land use to justify it. At this point, like many US cities, adding effective transit is a chicken and egg problem with land use.