> Ability to enter the roadway at any time, rather than after checking that it's clear.

Jaywalking doesn't depend on whether the road is clear or not. Try crossing an 8-lane stroad sometime even when it's "clear" for the moment. A car doing 50mph can get to that far lane way faster than I can, let alone someone who isn't young and in reasonable physical shape.

What we've really done is taken half of all land in every city and made it deadly to set foot on. A city that is supposedly built for people, but will kill you if you walk about 10 feet in most directions.