Differences in turbolift travel times could all be chalked up to congestion in the shafts, and the possible use of alternate routes to deal with such congestion... There could (and probably should) be at least two routes to choose from basically everywhere in the ship, perhaps even including the connecting neck.
What do we make of the "Turbolift 7" signs?
- Simply the ID number of this particular turbolift stop, moved from stop to stop as the show progresses?
- The number of a specific turboshaft, displayed at all stops along the shaft, and helping tell the user where this lift might go and where it might not?
- The number of a turbolift "line", meaning lifts from this location go along the standard route known as "7" unless otherwise instructed?
- The maximum capacity of lifts stopping here, in number of passengers?
- Not a sign at all, but rather an aesthetically pleasing display showing how many lift cabs are currently serving this stop, or how long till the next scheduled one?
- Sign establishing that this turbolift stop is on Deck 7, disregarding all contrary hints?