This cache is placed as part of the SFGRO event on August 8, 2021.
This is a quick multi. At the posted is a plaque from which you will glean the information needed to find the final cache.
Find the year the underpass was opened and call this ABCD
Find the digital root of the last name of the Director of Public Works and call this E.
Find the digital root of the councillor whose first initial is G. Call this number F.
Find the digital root of the last name of the councillor whose first initial is S. Take half that number and call the result G.
The final is hidden at N44 FG.CFE' W76 A.F(B-C)D'