First Street SW from 9th and 6th would make a really nice candidate for a traffic-limited zone. There's only three buildings on that whole stretch built in the past century (Brookfield Place, Len Werry,, and that ugly one across from the Palliser). This stretch would also have the benefit of being bookended by two sizeable plazas and include significant historic structures; the aforementioned Palliser, Grain Exchange, Lougheed Block.That section of Stephen Ave, Macleod Tr to 3rd St SW, has the highest concentration of heritage buildings in the city. Unfortunately, there are few other streets in downtown that can be replicated as a pedestrian experience. Virtually everywhere else are blocks of sterile office buildings, a few courtyards and uninteresting storefronts. It would be pointless to waste a lot of time and money trying to create an experience in other parts of downtown.
Whether vehicular traffic continues down 8th Ave, I think will depend on the final design recommendations for both Olympic Plaza and Stephen Ave. I betting it will be more pedestrian focused and less vehicular.
p.s When we talk about cars on Stephen Ave, we seem to forget the LRT line runs parallel, only one block north. The city should also be focused on increasing ridership, after business hours, in conjunction with the 21st century makeover experience.
Not that I'm necessarily saying cut traffic on First, but honestly I think it could really do with an addition of 50% or more to the width of sidewalks.