Many bridges in California have been retrofitted with cables to prevent the span from falling off the columns during an earthquake (lower right in photo below). Column caps were added on many bridges to create a wider landing place for the roadway rather than the narrower column tops. Columns have also been enclosed in steel jackets to prevent them from shattering or splitting during an EQ.
You get a lot of chances to examine these retrofits when stop-and-go traffic stops you under a bridge! ;>)