2-lane freeway

A two-lane expressway or two-lane freeway is an expressway or freeway with only one lane in each direction, and usually no median barrier. It may be built that way because of constraints, or may be intended for expansion once traffic volumes rise. The term super two is often used by roadgeeks for this type of road, but traffic engineers use that term for a high-quality surface road. Most of these roads are not tolled.

A somewhat related concept is a "four-lane undivided expressway". This is much rarer; a former example is some sections of U.S. Route 101 in northern California.

In Europe, the concept of express road, is related to road which are classed between a motorway and an ordinary road. This concept is recognized both by European union law and by UNECE treaty. This type of road is not very standardized, and its geometry may vary from country to country or within a same country. Those road are usually, but not always, reserved for motorized vehicle, and accessible with Limited-access road (see ). Some European union regulation considers the high-quality roads are 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». According to this same regulation «High-quality roads shall be specially designed and built for motor traffic, and shall be either motorways, express roads or conventional strategic roads.»

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. If the road is widened, the existing road is typically allocated to traffic going in one direction, and the lanes for the other direction are built as a whole new roadbed adjacent to the existing one. When upgraded in this manner, the road becomes a typical freeway. Many two-lane freeways are built so that when the road is upgraded to a proper divided freeway, the existing overpasses and ramps do not need reconstruction.

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Wikipedia