The first construction included installation of new traffic light access pits and ducts across the intersection of St Andrew and Great King Sts.
Construction was expected to begin on Monday.
However, Otago Regional Council support services manager Gerard Collings said until yesterday Fulton Hogan was still undertaking preparatory works in order to get on site, which was part of the ''normal process''.
The hub will be in Great King St between Moray Pl and St Andrew St and will become the centre of the city's bus network.
It will include 10 bus bays, electronic timetables, public toilets and a cafe kiosk.
The council has said work would be ''round the clock'', and the highest impact construction would be scheduled between 6.30pm and 6am.
At least one lane of the road would remain open during daytime hours and pedestrian access would be maintained.
The hub was expected to be operational in November.
