Retired now, so I don’t have a dog in this hunt, but for almost the final 30 years it was the time that it took to walk down from the first floor kitchen of my house, out of the front door, zap the fob on the up and over garage door, back the Black Cab out to the drive, zap the garage door back down, fire up the yellow TAXI light, and start looking for someone with their hand raised, or the on board monitor to go ding! and offer me a trip.
The commute home was rarely longer than 10-12 minutes, as I always waited until I was in The City, or London Bridge station before extinguishing the TAXI light, and heading for Rotherhithe, but I kept the monitor on, in the vain hope that it would offer me a trip from The City to SE London, and pay my way home.