AASHTO Bicycle Facilities Guide (American Association of State Highway and Transportation Officials Guide for Development of Bicycle Facilities)

The AASHTO Guide for the Development of  Bicycle Facilities has been developed in recognition that most bicycling takes place on roads that do not have dedicated space for bicyclists. It is intended to inform efforts to accommodate bicycle traffic in most riding environments—in addition to ordinary roadways, bicycle lanes, separated shared use paths and even sidewalks, under special conditions.
Instead of strict standards, the guide sets forth guidelines for attaining good design that is responsive to the needs of bicyclists as well as other road users. 
Traffic control devices approved by the MUTCD are expected to be used in conjunction with this guide.
This guide has been updated from the previous guide published in 1999. See the 1999 Introduction of the AASHTO Guide for the Development of  Bicycle FacilitiesPaid copies can be ordered from AASHTOFor the 4th edition, the price is $187 for non-members and $144 for members.  A video describing this new edition can be viewed here.