Here's a novel but probably not new idea:
Close traffic on Universtiy Avenue between Emerson and Middlefield (could be a little higher) to all traffic after 10.00 or 10.30 am each morning. Convert Lytton and Hamilton to one way streets going in opposite directions to encourage faster traffic flow (not speed) and allow restaurants to set up on the sidewalk and in the street like a European downtown (walking only)
Of course, the cross streets would be open for crosing from one side of town to the other. Make them one way going in opposite directions too.
We would have the best downtown in California with even more going on than now!