Here is how it would work.
First, ban all automobiles from the entire 15-mile length of the boulevard. Second, beginning at its Western Avenue station, bring the Metro Rail to street level and run it to and from the sea on two sets of rails in the center of Wilshire, which has four or more lanes down its entire length and is thus wide enough to accommodate the route. Third, create bus lanes running east and west for riders who want to make more frequent stops, leaving express service to the Metro Rail. Fourth, install protected bicycle lanes in each direction at the edges of the boulevard and provide inexpensive, self-service rent-a-bike stations every 300 yards (as in Paris) so riders can pick up a bike anywhere on Wilshire and drop it off where they like.