Cities around the country are moving to reduce the impact of highways and large arterial on local economic development and quality of life. They are doing it by replacing the dinosaurs of the transportation world (grade seperated highways) with at-grade multi-lane boulevards. Boulevards move high traffic volumes while creating a generous pedestrian realm and living environment by separating through traffic from local access lanes.
I spent twelve years of my life trying to define a way to tame the highway and calm the large arterial and was a contributing author to two manuals on such measures: Texas Access Manual and Context Sensitive Design . To date I have yet to see a six lane divided arterial with mixed use walkable development or one that is comfortable to peds and bikes as the consultant for the SM Wright redesign promises in this article.
It is a simple matter of speed. You must separate the cars and trucks moving at 35mph+ from the bikes moving at 10mph+ and the pedestrians walking at 3mph or less. This separation You must divide the speeds of the roadway with multi-lane http://www.sfbetterstreets.org/design-guidelines/street-types/multi-way-boulevards/