Design Bulletin for the issuance of the 2018 CDOT Roadway Design Guide.
CDOT Roadway Design Guide 2018
Issued on October 25, 2018. Includes 2018 revisions to the 2005 CDOT Roadway Design Guide.
Yellow highlights are content changes with green highlights being reference updates.
To differentiate between the types of highways, functional and contextual classifications have been developed so that engineers, administrators, and the general public can communicate about highways.
Chapter 2 discusses characteristics of vehicles, pedestrians and traffic that act as criteria for the optimization or improvement in design of the various highway and street functional classes.
There are elements of design common to all classes of highways and streets, which include sight distance, superelevation, traveled way widening, grades, and horizontal and vertical alignments.
Types of Cross Section Elements
Local roads or residential streets primarily serves as access to a farm, residence, business, or other abutting property. The through traffic is local in nature and extent rather than regional, intrastate, or interstate.
This chapter is subdivided into rural collectors and urban collectors. Consult Chapter 3 and Chapter 4 of this Guide for details on the basic design elements applicable to these classification of roadways.
Rural arterials range from two-lane roadways to multilane, divided controlled-access arterials. Urban arterials carry large traffic volumes within and through urban areas. Their design varies from freeways with fully controlled access to two-lane streets. Consult Chapter 3 and Chapter 4 for details on the basic design elements applicable to these classification of roadways.
The highest type of arterial highway is the freeway, which is defined as an arterial highway with full control of access and no at grade crossings or connections. This chapter identifies the various types of freeways, emphasizes selected features, and discusses other design details unique to these freeway types. Consult Chapters 3 and 4 for details on the basic design elements applicable to this classification of roadway.
An intersection is defined as the general area where two or more highways join or cross, including the roadway and roadside facilities for traffic movements within it. These movements may be handled by various means, such as signals, signing, and channelization, depending on the type of intersection.
An interchange is a system of interconnecting roadways in conjunction with one or more grade separations that provide for the movement of traffic between two or more roadways or highways on different levels.
Access management is the planned and regulated interaction between the roadway network and property access.
This Chapter provides guidance and direction regarding the requirements for the design of accessible pedestrian facilities so they are accessible to all potential users in all roadway environments.
A low-volume local road has an average daily traffic volume of 400 vehicles per day maximum.
Multimodal transportation is a key element of CDOT’s mission in providing improvements to the statewide transportation system. CDOT has adopted a Policy Directive and a Procedural Directive to improve the accommodation of bicycles and pedestrians in CDOT programs. (Unchanged from the 2005 Guide.)
