As if the impending BARTpocalypse wasn't enough to put commuters on edge, Muni will also be closed every night for the next six months starting Friday. 

Starting July 31, work to replace the subway system’s outdated radio and emergency telephones will shut down the Market Street Subway and Twin Peaks Tunnel, thus stopping all rail service between Embarcadero and West Portal stations beginning at 9:30pm. 

To ease some of the congestion (and the ire) of passengers, Muni is also setting up shuttle buses scheduled to depart every eight minutes along the length of the subway. Regular service is scheduled to resume at 5am daily, and any service outside the two affected tunnels will continue to run normally.