Remember that Improv Everywhere "sidewalk tourist lane" prank? London is taking it to heart, with an actual proposal to divide its busy Oxford Street sidewalks into slow and fast lanes. Cute. But their plan has two prominent flaws.

FLAW THE FIRST: The WSJ reports that the line on the sidewalk would merely be "virtual." "Under the plan...maps available at airports, hotels and other traveler spots would tell visitors to cling to buildings. The directive would also be written onto local area maps outside subway stations and at busy intersections." So it's dependent on tourists reading and understanding simple signs and maps? Impossible.

FLAW THE SECOND: Coddling rule-breakers. "The proposal...wouldn't call for traffic cameras or fines for violators. Those in the fast lane couldn't legally be stopped from eating, smoking, talking on the phone or walking dogs."

Erect a concertina wire-topped fence down the middle of the sidewalk and institute mandatory and immediate canings for lane-shifters, and we'll be the first to salute you.