The 1956 span of the Gandy Bridge between Tampa and St. Petersburg was closed to traffic in 1997. It was renovated for pedestrian and bicycle use, but closed "indefinitely" in 2008 when it was deemed structurally unsafe. It remains in place, as of March 2013, as government officials decide whether to demolish the entire bridge or demolish the center span and retrofit the remaining stubs for use as fishing piers.
An unused highway is a highway or highway ramp that was partially or fully constructed, but was unused or later closed. An unused ramp can be referred to as a ski jump, stub ramp, stub street, stub-out, or simply stub.
Some examples of reasons for unused highways include:
An older portion of roadway being left unused by a highway realignment. The abandoned Pennsylvania Turnpike is one instance of this, where two two-lane tunnels and four-lane approaches were bypassed with four-lane cuts. The old tunnels and approach roadways in this case are being rehabilitated for a multi-use trail. Some parts of the A1 and A3 motorways in Italy have been recently abandoned after some dangerous, curvy and narrow mountain stretches were replaced by wider and straighter alignments through new viaducts and tunnels. In many roads in the Alps, some dangerous sections were replaced by tunnels and the abandoned parts are usually closed to traffic and used as hiking trails.
A road which existed to serve a bridge becomes a dead-end once the bridge is demolished or left to deteriorate to the point where it can no longer be safely used. This is common on some older alignments of U.S. Route 66 which were bypassed, as the route was changed through multiple realignments before becoming a decommissioned highway in 1985.
A road becomes a dead-end once a level railway crossing is closed and replaced by an overpass\underpass some distance away from the former level crossing.
Highway construction begins but is canceled, possibly because of a freeway revolt. Examples include the Pennsylvania Route 23 "Goat Path" east of Lancaster, which was graded for a four-lane expressway. The project was canceled before paving could commence, so the roadbeds were planted over with grass. In London, the M11 motorway has two short unused slips at Junction 4 (Charlie Brown's) which would have been a link for the M12 motorway to head east into Essex. The RH Thompson expressway in Seattle was never built, leaving stub ramps. Likewise, there are stubs for the never-built Inner Belt in Boston, Massachusetts. There is a similar situation on the motorway A4 near Delft, Netherlands, where works started in the 1960s but were stopped (and restarted recently). In Italy the motorway A31 ends in the middle of nowhere because works for extending it towards the A22 were stopped after protests in the late 1970s. The 5-km-long Guinza tunnel, part of the planned Grosseto-Fano expressway was completed in 1991 and never opened to traffic.
Stubs are built to connect to a highway that is not yet constructed. These stubs ramps are very common in the state of North Carolina, where they will eventually connect to new stretches of I-73, I-74, I-485 and I-840, among others, along the Greensboro Urban Loop.
The highway is used for a different purpose than originally intended. The east end of Interstate 70 in Baltimore and the stub of Interstate 95 inside the Capital Beltway northeast of Washington are two examples due to cancellations of their alignments within the inner city. Both of these stubs are used for park-and-ride facilities. In England, improvement works in 1987 rerouted the A47 in Rutland near Wardley resulting in an unused stretch of carriageway being left behind which functions only as access to a transmitting station. Part of the A2 in Kent was realigned in 2009, leaving a substantial part of the original road intact. Part of the road has been made into a public park. On Interstate 90 near Albany, New York, an interchange was built for the never-to-be Interstate 687; that interchange (labeled as Exit 5A off I-90) now serves as an exit for Corporate Woods Boulevard. The exit ramps occupy nearly as much space as the area they serve.
The highway has unused lanes. The 1000 Islands Parkway contains two "ghost lanes" for its entire 40 km length. Its right-of-way is four-lane divided as it was part of Highway 401, Canada's busiest highway, during that freeway's construction. When the 401 was ultimately completed in 1968, the final 1000 islands bypass took a path further inland. Two lanes of the original four lane waterfront right-of-way were retained and used for the scenic parkway, the rest becoming small pedestrian or bicycle trails laid out in an otherwise-vacant freeway-grade right-of-way.