Most of the variance in my former commute was from the Green Line to Hell. This was a couple of years ago, but it still seems pretty bad.

I remember that it could take between 45 minutes and 2 hours to get from Medford to the Longwood Medical Area on the T. Let's call it 1.25 with a 95% confidence interval of (1.0, 2.0) It was a consistent ten minute walk to an express bus that would drop me at the green line in 15 more minutes (25 minutes). The green line would ten take 20 minutes to 1.5 hours to get me one stop beyond Longwood. I'd sometimes take the orange line to Roxbury Crossing and then walk a mile to the medical campus to save a lot of time. (NOTE: RUGGLES stop isn't far a walk from Longwood and there are shuttles).

Taking the shuttle from Harvard Square (as a Harvard employee) took between 50 minutes and 1.5 hours. 1.25 with 95% CI of (1.0,1.5) hours. This required some biking or a couple miles of walking (both to the 96 bus and from the Medical School to Mission Hill)

Driving at early rush hour: typical 40 minutes with a 95%CI of (30, 60) minutes.

Biking was a consistent 50 minutes with a 95%CI of (40,60) minutes once I got into shape, largely traffic independent because of local road route selection.