There will be as much traffic on a road as there are people willing to put up with it. Urban planners can reduce traffic by introducing alternative transportation methods and either raising costs for cars (congestion pricing, dynamic parking pricing, etc) or making them less convenient (reduce parking, fewer cars lanes, etc). Some transportation options, like buses and bikes, become more attractive when infrastructure prioritizes them over cars (dedicated rights-of-way to avoid getting stuck, separation from cars for safety, bicycle parking, etc).

Infrastructure rightly prioritises the most useful and most efficient modes of transportation, and gives less priority to that which is less useful and efficient. That's rational and correct, no need to change that.

Road space is currently unmetered. Parking space is also often unmetered or underpriced. Should it be the same price for everyone to drive 18-wheelers and RVs and cars and mopeds into the center of a city? Bicycles are the most efficient mode of transportation in terms of energy, except for the densest urban subways.

Cars are a local maximum of utility that doesn't require much coordination or planning. They took advantage of pre-existing public roads and then crowded out all other road users, and subsequent roads were simpler to design and plan for cars than for mixed use with other road users.

Make society less efficient and less convenient? Why? We already have electric cars, and electric 2 wheel mopeds/motorcycles too if you want to complain about "space"

The lane closure (or rather: repurposing) now provides fast access for emergency vehicles. Given that most of the roads they’ve made these changes on are the direct route to the university hospital it’s a good outcome.