"The fatal flaw at the heart of the system is priority. [...] The unseen spanner in the works is the idea of main road priority." He fiddles a bit with a story

"The fatal flaw at the heart of the system is priority. [...] The unseen spanner in the works is the idea of main road priority." He fiddles a bit with a story about a woman and a pram, but doesn't actually address why this is a bad idea. While access and crossings can be improved in places, letting traffic flow fast and freely on main roads seems like a fundamentally good idea to me?