In Puerto Rico arriving on a Pan Am 747 a few years ago (about 1973?) we got four airbridges out to the aircraft. One to the front 2 doors on each side. We got up and kept walking from near the back. No stopping/queing to get off etc. We were all off in about 4 mins from memory. Once the pax were off the two on the right were taken away for the catering to be done then put back for boarding. All very quick & efficient.