Passenger lift traffic calculations Lift traffic calculations are usually based upon the recommendations within British Standards BS5655 : Part 6 : 1990 and CIBSE guide D:2000 - Transportation Systems in Buildings. As an example we detail below a typical passenger lift traffic demand calculation ; Building type Number of floors above main entrance Number of floors below main entrance Average floor population above main entrance Total population above main entrance Floor to floor height above main entrance Floor to floor height below main entrance Total travel Standard office, diversified tenancy 3 0 40 people (20 rooms x 2 guests - estimated) 120 people (estimated) 2.9 m 2.9 m 8.7 m Lift drive Lift configuration and duty Car internal dimensions Door entrance width Door type Number of entrances per car Reduction geared traction 2 x 10 person or 800 kgs. 1350 wide x 1400 deep 800 mm Centre opening 1 Rated speed Handling capacity Round trip time (rtt) Interval 1.0 m/s 22.63% (27 people) 44.2 seconds (approx.) 22.1 seconds (approx.)