Scott Donyon has a problem with pedestrian malls. As he writes on the Better! Cities & Towns blog:
The idea seemed solid. Give multiple downtown blocks over to pedestrians and, in the process, take on the new suburban malls with a compelling destination to draw crowds back downtown. Only, in most cases, it didn’t really work out that way.
Here’s why: The problem — at least the most visible one — was that we had relinquished our streets to the automobile, relegating all other users to second or third class status. We had taken the complexity of the public realm and dumbed it down into a single-use car sewer. Cars good, walking bad.
So how did we try to fix that? By doing the exact same thing, except in reverse. This time it was cars bad, walking good, which presents a similar set of problems because community doesn’t thrive in the all-or-nothing extremes of complexity reduction. Instead, the workable solutions tend to be the ones found in the messy middle ground, where culture and commerce intersect and competing interests are confronted and reconciled.
I agree that all-or-nothing approaches rarely work, but I don't believe the problem with pedestrian malls is eliminating vehicles per se. As this study from earlier in the year explains, walkable centers generally don't have a sufficient market within their pedestrian shed (the distance people will walk to get to the center) to support their businesses. Instead, they need to "import" customers from surrounding locations via transit, biking, or driving--modes that accommodate longer trips. A sustainable pedestrian mall will allow for these trips, even if it doesn't direct them straight through its core.
That's one reason that Estes Park is so ideally suited for a pedestrian-mall-type road closure: the parking lots that ring main street allow outsiders to drive to the downtown perimeter and park, then leave their vehicles behind and browse on foot. (And why is window-shopping on foot better than driving through a main street? It encourages impulse buys: you're much more likely to pause for an ice cream cone if you don't have to search for parking first.)