The underpass was an integral part of the original design. Amsterdam had allowed the building of the museum on the condition that the existing street would remain open to all traffic. It was after all the gateway to the new developments in Amsterdam South. The underpass at street level (often called ‘tunnel’ but it really isn’t that) was wide enough for a tram line. But that was never built. The underpass was open to motor traffic until 1931. The museum director at the time had already been asking for a traffic ban since 1925 but only achieved the compromise that motor traffic would be banned. Consecutive directors tried to turn the central underpass into a main entrance three times, in 1945, 1963 and 1975. But the city refused to give up the vital traffic connection.