Considering what happened with the Nimitz Freeway pancaking during an earthquake, going above-and-beyond should be done in a place like San Francisco.
The reference to the pancaking of the Freeway was that the freeway had two layers. The earthquake caused the top layer to come down on the bottom layer. Some folks were crushed in their cars as a result, as I recall.
They will all fail, given time. You can extend the time but it will affect other considerations, appearance, cost, etc.