How do you turn an ordinary Friday morning with ordinary (bad) San Francisco traffic into an unending gridlocked morass?
There are probably many, many answers to that question, but here's today's: Crash a big rig at the eastbound entrance to the Bay Bridge in San Francisco.
That's what happened just before 5 a.m. Friday, when a semi jack-knifed as it started onto the span's lower deck just as the morning commute swung into high gear. The crash and subsequent diesel fuel leak caused the California Highway Patrol to reroute traffic off the eastbound skyway approach to the bridge and close all but one eastbound on-ramp.
The crush of traffic moving to that single functioning ramp -- Sterling Street, off of Bryant just east of Second Street -- stopped traffic on northbound U.S. 101 all the way back to South San Francisco and triggered gridlock across much of San Francisco's South of Market district. The mess on city streets caused traffic on the westbound Bay Bridge to back up.
By noon Friday, the CHP said the big rig had been dragged across the bridge to Oakland, the fuel spill had been mopped up and all lanes and on-ramps were open. The big rig's driver reportedly escaped the crash with minor injuries.
But the traffic mess continued through midday Friday, with Waze users across SoMa reporting being trapped at a standstill and 511.org showing slow or stopped traffic from the old Candlestick Park exit on northbound U.S. 101. Traffic heading into the city from the East Bay was at a crawl from Ashby Avenue on Interstate 80. Traffic was also jammed on the popular West Grand Avenue entrance to the bridge from West Oakland.