Factors that operators have been known to prioritise over passenger access include staff convenience, short term profitability, time-keeping (if passengers in wheelchairs take a long time to board). Most city centre railway stations require passengers to climb to high-level platforms to take a train. The reason is that the city was there before the railway, so the tracks were built well above ground level to avoid cutting the existing street network. It is less expensive to build the tracks well above ground, on embankments, than to tunnel underground. Figure 2a shows Leipzig main station, which now has an elevator to platform level, but located behind of the staircase where most passengers do not use it, Figure 2b. Lack of knowledge and poor signing?