The answer is right in the linked article:

> Repurposing some of Columbus Avenue’s asphalt to create new “green infrastructure” that would narrow the roadway, calm traffic, and provide an additional buffer between the Southwest Corridor and motor vehicle traffic.

I’m all for it. We devote far too much space to the most geometrically inefficient mode of transportation (single-occupancy automobiles). This redesign will increase the throughput capacity of the avenue with respect to the number of people.