Two-lane expressway

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 freeway". This is much rarer; a current example is U.S. Route 101 in California through Humboldt Redwoods State Park.

In Europe, the concept of express road encompasses roads which are classified between a motorway and an ordinary road. It does not necessarily have two lanes. This concept is recognized both by European Union law and under the UNECE treaty. This type of road is not very standardized, and its geometry may vary from country to country or within a same country. These roads are usually, but not always, limited-access roads. 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". 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." 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]