CDOT Roadway Design Guide 2023

Chapter 3 - Facility Type – Road

A road facility type (Road) is generally characterized as a two or more-lane roadway with shoulders and roadside ditches, mainly found in a rural, low-density settings.

Chapter 4 - Facility Type - Street

A Street facility type (Street) is generally characterized by the inclusion of curb and gutter, sidewalks, and storm sewers in more dense, urban contexts that may include on-street parking, bike lanes, and transit stops.

Chapter 5 - Facility Type Freeway, Expressway, and Interstate

A Freeway or Interstate is a divided highway with full control of access and two or more through lanes for the exclusive use of traffic in each direction. Traffic flow on a Freeway is unhindered because there are no traffic signals, intersections, or at grade crossings with other roads, railways, or multiuse paths.

Chapter 6 - Elements of Design

The design of Roads; Streets; and Freeways, Expressways, and Interstates in differing context classifications are treated differently. However, common to all facility types are several principal elements of design: sight distance, cross slope, travel lane width, and horizontal and vertical alignments.

Chapter 7 - Cross Section Elements

(Rev: 2-20-2024) Cross sections will often vary throughout a project length to adapt to different context zones and identified constraints.

Chapter 8 - Intersections

(Rev: 2-20-2024) An intersection is defined as the general area where two or more roadways join or cross, including the roadway and roadside facilities for traffic movements within it.

Chapter 9 - Roundabouts

A roundabout is a form of a circular intersection in which traffic travels counterclockwise around a central island and entering traffic must yield to circulating traffic.

Chapter 10 - Grade Separations and Interchanges

Grade separations of intersecting traffic lanes facilitate uninterrupted flow or traffic, resulting in the greatest efficiency, safety, and capacity for traffic and the least amount of air pollution. An interchange is a system of two or more interconnecting roadways or highways and one or more grade separations.

Chapter 11 - Access Control and Management

Access management is the planned and regulated interaction between the roadway network and property access. It is an intentional strategy to reduce conflict points and to maximize network efficiency while supporting a safe and efficient transportation system that also supports a diversity of travel modes.

Chapter 13 - Bicycle and Pedestrian Facilities

Bicycle and pedestrian modes of transportation are key elements of CDOT’s mission to provide an integrated multimodal transportation system to accommodate walking and biking as viable transportation modes that contribute to the health, safety, equity, and equality of our communities.

Chapter 14 - Bridges

(Rev: 2-20-2024) This chapter addresses the basic issues when designing a roadway project that includes major or minor structures incoordination with the other CDOT specialty groups.

Chapter 16 - Noise Guide

This chapter is intended to help designers understand issues related to highway traffic noise. This includes understanding the applicable federal and state regulations and guidelines, traffic noise analyses for specific projects, highway traffic noise mitigation measures, and construction noise mitigation measures.