I-70 Glenwood Canyon—Design Concept

A critical section of Interstate Route I-70 follows the Colorado River through Glenwood Canyon in western Colorado. Physical constraints imposed by the narrow winding Canyon, coupled with environmental concerns, present a major design and construction challenge. A design team of architects, environmentalists, geologists, and engineers made a detailed on-site evaluation of the project and reviewed such data as river flooding records; snowfall and winter icing problems; existing vegetation, fish, and wildlife species and habitats; and recreational and scenic sites. The recommended design embodies a terraced concept, avoiding excavation of the canyon walls. The design meets Interstate criteria for 50-mph (80-km/hr) speeds, with two 24-ft (7.3-m) roadways plus 10-ft (3-m) shoulders on the right side of each roadway. Access is provided to several scenic points, with picnic and restroom facilities, access to the river, and hiking trails. A bicycle path is provided through the entire section.