Number of SGM Hikes and Travel Time To Trailheads From Caltech
Over half of the hikes listed at this site are within 45 minutes travel time to the trailhead from Caltech, as measured from the intersection of Wilson Avenue and California Boulevard:
The location of the trailheads, color-coded by travel time, is not surprising:
Explanation of map
List of Hikes Sorted by Travel Time from Caltech explains how to convert these times to those from other locations.