While not fitting the definition of street typologies, two other categories of streets are noteworthy because of their unique character and evolution in the Denver street system -- Landmark Streets and One-Way Couplets.
Landmark Streets have a particular significance in Denver’s history because of their influence on the development and unique physical character of the city.The Landmark Streets system, also known as the Historic Denver Parkway System, has significantly shaped the development and unique physical character of Denver. Today, because of their connectivity throughout central Denver and the Denver region, Landmark Streets serve key functions of mobility and land access. Today, Landmark Streets, because of their connectivity throughout Central Denver and regionally, serve key functions of mobility and land access. Landmark Streets are specially designated, and require additional review and approvals for proposed development, zoning changes, and roadway projects.
One-Way Couplets are pairs of one-way streets that function as a single higher-capacity street. Couplets are usually separated by one city block, allowing travel in opposite directions and are generally designed to accommodate a higher transportation capacity than an equivalent two-way street.
Both Landmark Streets and One-Way Couplets may functions as arterials, collectors, or local streets. One-Way Couplets may also function as Downtown Access streets. Because of the land uses adjacent to the streets, One-Way Couplets can be designated any of the five street typologies: Residential, Main, Mixed-Use, Commercial, or Industrial. Landmark Streets are also characterized by several street types as well, including Residential, Main Street, or Mixed-Use.