Design Flexibility

“A ‘one-size-fits-all’ design philosophy is not Departmental policy...”

“This guidance allows for flexibility in applying design standards and approving design exceptions that take the context of the project location into consideration; which enables the designer to tailor the design, as appropriate, for the specific circumstances while maintaining safety.”

- from Caltrans Highway Design Manual (HDM), Chapter 80

To reaffirm the Caltrans commitment to providing flexibility while maintaining the safety and integrity of the state highway system, and local streets and roads under the jurisdiction of cities and counties, the Department released a memorandum titled "Design Flexibility in Multimodal Design"(PDF)dated April 10, 2014. The memorandum highlights the flexibility provided in existing Caltrans guidance, positive steps already taken in underscoring the importance of multimodal design, and recognizes the value of other guidance in supporting planning and design decisions made by state and local decision makers statewide.

The Highway Design Manual (HDM) establishes uniform policies and procedures to carry out the State highway design functions of the Department. For the most up to date and current version, HDM users are encouraged to use the online versions and can even sign up to be notified automatically of any changes and updates.

Main Street, California - A Guide for Improving Community and Transportation Vitality - California State Highways that also function as main streets through communities are challenged with balancing the public’s need for roadways that provide local, regional and statewide connections, with local needs for a vibrant community street.


Class IV Bikeway Guidance (Separated Bikeways/Cycle Tracks) (PDF) – Caltrans Design Information Bulletin No. 89, 12-30-15

Class IV Separated Bikeways: Approved for Use in California (PDF) An easy guide for implementation by the California Bicycle Coalition August 2016

Guide for the Development of Bicycle Facilities, 4th Edition - AASHTO 2012 (order for purchase)

Urban Bikeway Design Guide – NACTO March 2014

Bicycle and Pedestrian

Bicycle and Pedestrian Facility Design Flexibility Memo (includes examples and resources) - US Department of Transportation Federal Highway Administration 8-20-13

Best Practices D11 Complete Streets Design Flex (PDF)

California State Bicycle and Pedestrian Plan – Caltrans

Yes We Can – Bicycle and Pedestrian brochure (PDF) – Caltrans


Achieving Multimodal Networks: Applying Design Flexibility and Reducing Conflicts – FHWA August 2016

Assembly Bill No. 93

California Manual on Uniform Traffic Control Devices (CA MUTCD) Revision 1 – Caltrans 12-9-15

California Traffic Control Devices Committee

Deputy Directive 64-R2 Complete Streets - Integrating the Transportation System (PDF) – Caltrans 10-17-14

Design Flexibility in Multimodal Design Memo (PDF) - Caltrans 4-10-14

Design Information Bulletins - Caltrans

Design Standards - FHWA

Design Stewardship Delegation - Caltrans

Direction on Flexibility in Design Standards Administrative Resolution (PDF) - Standing Committee on Highways (SCOH) 5-25-16

Director’s Policy DP-23-R1 Energy Efficiency, Conservation, and Climate Change (PDF) – Caltrans 6-6-07

FAST ACT Design Standards – FHWA April 2016

Green Book – AASHTO 2011

Highway Design Manual - Caltrans

Highway Safety Manual – AASHTO March 2016

Livability in Transportation Guidebook - FHWA

Main Street, California – Caltrans Nov 2013

Mitigation Strategies for Design Exceptions – FHWA 5-1-14

Performance Based Practical Design – FHWA

Road Diet Informational Guide – FHWA Nov 2014

Urban Street Design Guide – NACTO Oct 2013