This has been happening in smaller cities, too. 8th Street in downtown Boise has always had sidewalk dining, but now the street will be closed to traffic. The city installed retractable bollards a couple of years ago, so they can easily block traffic.
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People have been clamoring for this for years. There are literally dozens of restaurants along the street that need the space for social distancing, but this could be the start of a permanent change.