I know when I was in Amsterdam several times last year, I found that lots of the canal streets had pop-up barriers that would close off traffic during certain times of day. They are VERY effective, as they are basically hydrolic cylinders that pop up into a pole like you see outside stores. So, when up, relax! No cars!
courtesy
www.fugly.com
If you go to Spain, there are plenty of the older street grids in Madrid, Barcelona, and especially Seville lack motorized vehicles. It's because the grids are on the same alignment as they were in the Middle Ages! (Seville especially did not undergo the "euro-restoration of grand Boulevards" that occurred in other cities like Paris and Berlin). Great stuff when out and about, not needing to worry about cars! But you can get dis-oriented and lost in the narrow street labyrinths...a plus in my book.
You should go to Spain. I highly recommend it for no cars! The Moorish street grids from centuries ago still dominate many of the modern urban city plans, especially in the south.