Boy, This takes me back. In the early 70's, when I was a very active cyclist, I took part in a race during "Bicycle to Work Week." The contestants were a driver, a commuter taking SEPTA, and me riding my trusty Gitane, as I did every day.
The race took place between Robbins and Frankford Avenues in the lower Northeast, and Drexel University, where I was a student. This meant that the driver had to find a place to park, while the SEPTA commuter needed to take the 66 Trackless Trolley, the MFSE, and walk (or run) from 30th and Market to 32nd and Chestnut.
The car driver won.
I came in 50 seconds later (huffing and puffing only slightly).
The SEPTA commuter came about five minutes after me.
As was mentioned, this kind of race needs to be run multiple time to get an accurate picture of which mode of transportation is the fastest. Of course, being the fastest may not be the most important point about taking public transportation. There are other factors to consider, such as:
The availability of parking and parking fees.
The type of commute - depending on the temperament of the commuter, he or she may find taking one mode of transportation more relaxing than the other.
The convenience of SEPTA versus driving.
The reliability of one mode of transportation over another. One may put up with service delays easier than traffic delays.
The satisfaction one gets from keeping one more car or SUV off the crowded roadways and streets.
The savings on insurance, fuel, tires, parking, etc..
Despite all the problems with SEPTA, I still find it the best way to get to most places.
I used to be a daily commuter, now I use SEPTA for fun.