The Overseas Highway: Leonida Viaduct Guide

Corridor Specifications & Tactical Viaduct Geometry

Among the most technically impressive cartographic achievements confirmed in Grand Theft Auto VI is the recreation of the Florida Overseas Highway (US Route 1)—a sprawling civil engineering masterpiece that bridges open ocean waters between the metropolitan mainland of Vice City and the remote, sun-bleached subtropical Keys.

Spanning an estimated 28 to 35 in-game miles (equivalent to approximately 8 to 12 minutes of continuous high-speed transit in a supercar), this elevated concrete spine represents both the ultimate open-throttle straightaway and a deadly tactical bottleneck.

Cartographic Sections & Key Waypoints

[Vice City Mainland / South Shore]
                │
                ▼ (Segment 1: Mainland Marsh Causeway)
       [Kelly County Toll Gantry]
                │
                ▼ (Segment 2: The Grand Viaduct / 7-Mile Analog)
       [Historic Abandoned Rail Trestle] ─── (Parallels Modern Highway)
                │
                ▼ (Segment 3: Mid-Keys Archipelagos & Roadside Hubs)
       [Marathon Sound Marina & Motels]
                │
                ▼ (Segment 4: Southern Keys Ocean Terminus)
        [Key Settlement Marina & Southern Terminus]

Segment 1: Mainland Marsh Causeway (Vice-Dale to Kelly County)

Evidence Status: Official
Real-World Basis: Card Sound Road / US 1 Cross-Key Causeway
Topography: Low-lying four-lane divided asphalt hemmed in by dense mangrove swamps, tidal drainage canals, and roadside bait shacks.
Hazards: Roaming alligators crossing lanes during rainstorms; soft unpaved shoulders that pull speeding vehicles into deep mud ditches.

Segment 2: The Grand Viaduct (The Seven Mile Bridge Analog)

Evidence Status: Official
Real-World Basis: Florida Seven Mile Bridge (Knights Key to Little Duck Key)
Topography: A seamless, elevated multi-mile concrete span suspended 65 feet above turquoise ocean shallows.
Architectural Highlight: Runs directly parallel to the crumbling, rust-streaked ruins of the Historic Overseas Railway Bridge, originally built in 1912. The abandoned railway features broken spans, rusted iron girders, and secret ramps ripe for extreme stunt jumps onto following cargo barges.

Segment 3: The Mid-Keys Hospitality Strip

Evidence Status: Observed
Real-World Basis: Islamorada & Marathon Keys
Topography: A sequence of inhabited barrier cays linked by short connecting causeways. Features neon roadside dive motels, tiki bars, deep-sea charter slipways, and fueling depots.
Safehouse Potential: Documented motels provide ground-floor parking spots directly outside room doors, mirroring Jason and Lucia’s safehouse motel sequences in Trailer 1.

Segment 4: Key Settlement Southern Perimeter

Evidence Status: Estimated
Real-World Basis: Key West / Old Town / Naval Air Station Key West
Topography: The southwesternmost tip of Leonida (Mariana County). Narrow colonial residential streets, historic wooden conch cottages, cruise ship terminals, and an isolated radar station.

Tactical Roadblock & Pursuit Dynamics

Because the Overseas Highway is bounded on both flanks by open ocean, it represents the most extreme chokepoint in Leonida’s transport grid.

1. Police Spikestrip Roadblocks

During high-heat pursuits (3+ Stars), law enforcement establishes reinforced tactical roadblocks across the narrow dual-lane sections of the elevated viaduct. Unlike mainland highways, there are no grassy medians or exit ramps to skirt around.

2. The Railway Bypass Vector

Players driving off-road motorcycles or compact high-clearance 4x4s can exploit the parallel abandoned railway trestle. While jagged sections require precision jumps across yawning 40-foot gaps, the old railway is entirely inaccessible to standard police cruisers.

3. Emergency Oceanic Bailouts

If boxed in by SWAT Bearcat APCs, drivers can crash through the outer bridge barrier into the Atlantic below. Because the fall is survivable into deep water channels, a pre-placed speedboat or jet ski (marked via our Interactive Map Waypoint Studio) enables an immediate offshore getaway.

Route Telemetry

Using our map’s route measurement engine:

Direct Distance: ~18.4 km (~11.4 miles)
Highway Routing Length: ~24.8 km (~15.4 miles)
Supercar Transit Time (@ 210 km/h avg): ~7 minutes 05 seconds
Cruiser Transit Time (@ 120 km/h avg): ~12 minutes 24 seconds

Plan your route, mark tactical refueling points, and explore the complete viaduct network on our Interactive Map of Leonida.