We can't drive GTA 6 yet. What we can do is read the visible road network and pick the routes that look most distinctive. This is editorial speculation, clearly framed - the routes here are picks, not road tests.
For the underlying road network, see the state highways piece.
The Keys bridge route
The headline route. From southern Vice City out across the bridges, hopping from island to island toward the Key West analogue. Long water visible on both sides. Distinctive enough that it's likely to be one of the most-driven routes in the game. We have a dedicated page on this in the Keys bridge route piece.
The coastal interstate
From Vice City north along the coast through the suburbs and into the rural towns. A long, fast drive with the ocean visible to the east. Probably the cross-map equivalent of GTA V's run from Los Santos up the Pacific Coast Highway.
The wetlands cut
An east-west or diagonal route that crosses the wetland region. A road through saw grass and cypress, water on both sides, occasional stilt houses. Less hospitable than the coastal route, more visually distinctive.
The orange-grove run
A secondary route inland through agricultural Leonida. Slower, narrower roads. Trailer aerials show this kind of route between the orange groves and the small towns. The kind of drive that exists for atmosphere rather than for a destination.
What we can't pick yet
Mountain routes (Florida is famously flat - we discuss this on the elevation piece). Specific bypass routes around Vice City. Off-road or trail routes - Rockstar typically ships these and the trailers don't show them. Traffic congestion patterns - we don't know peak vs off-peak behaviour.