Slow Streets is a Vancouver based urban planning and design group. Their website features the biography of Darren Proulx who describes himself as a plangineer of places, active transportation and tactical urbanism to create great cities for people. The group's position is that "A street is more than simply about moving automobiles. Reconsidering the use of streets can achieve significant and positive impacts for cities."
Slow Streets contains enough information that anyone should be convinced that streets are not just for vehicles. The blog shows examples from around the world to bolster this view.
It's well worth a visit!