Some European Union regulation considers the high-quality roads to be roads "which play an important role in long-distance freight and passenger traffic, integrate the main urban and economic centres, interconnect with other transport modes and link mountainous, remote, landlocked and peripheral NUTS 2 regions to central regions of the Union".
Eurostat and the United Nations Economic and Social Commission for Western Asia define an express road as a limited-access road that has signs reserving the roadway for specific categories of motor vehicles and that prohibits stopping and parking.
[1][2] Two-lane freeways are usually built as a temporary solution due to lack of funds, as an environmental compromise or as a way to overcome problems constrained from highway reconstruction when there are four lanes or more.
By this definition, Super-2s can be considered the first stage of project which is expected to become a full freeway, with the transportation authority owning the land necessary for the future adjacent carriageway.
Many super-2 expressways are simply just short transitional segments between surface street and four-lane divided freeways.
Other super-4 expressways include the Hanlon Parkway in Guelph and Black Creek Drive in Toronto, both which have sufficient right of way to allow for interchanges and overpasses to replace the at-grade crossings.
When a super-2 expressway is converted to a four-lane divided freeway, artifacts on the existing roadbed such as double yellow lines or broken yellow lines in passing zones are removed in favor of road markings for four-lane divided expressways.
These expressways, however, only have partial access control with at-grade intersections commonly available like most other federal and state roads.
A portion of State Route 80 in the vicinity of Bisbee is a two-lane expressway with an interchange at West Boulevard and Tombstone Canyon Road (Historic US 80).