Two-Lane Highways

Two-lane highways, which have one lane per direction, are unique operationally since they may allow passing using the opposing traffic stream. According to the US Federal Highway Administration [1], two-lane highway facilities represent about 97% of the total highway system and more than 65% of the total nonurban vehicular travel in the United States. Hence, two-lane highways provide most of the primary interurban highway networks and are the basis of the secondary highway and collector networks. Figure 13.1 provides a sketch of a two-lane highway.