An afternoon and evening of downtown Seattle gridlock last March proved a point: There’s nothing like an overturned semi on S.R. 99, carrying a load of fish, to focus minds at City Hall. In classic bureaucratic jargon, city officials on Friday unveiled a new series of plans for “enhancing traffic management practices” to better handle the next street-clogging incident. It will include “a formal memorandum of understanding between departments and detailed clearance policies and procedures for each department.” Seattle puts it all together when it comes to gridlock dangers: The city is shaped like an hourglass between two bodies of water. It has steep hills. An accident on I-5 or [...]