-> The Institute for Transportation Engineers (ITE) has released a guide of best practices on interchange designs that accommodate pedestrians and cyclists in the United States and Canada. It identifies precise dimensions, safety features, signage, pavement markings, and design geometries as best practices that may provide insight into future updates of statewide or federal highway design manuals. (Recommended Design Guidelines to Accommodate Pedestrians and Bicycles at Interchanges: http://bit.ly/1LhAuyH)
from CenterLines, the e-newsletter of the National Center for Bicycling & Walking.
[B' Spokes: Note state law calls for "best engineering practices" so here you go. Ref: http://www.baltimorespokes.org/article.php?story=20111025010622931 ]