High public interest in the bus tours of Christchurch's cordoned-off city centre has overloaded the phone booking system.
The bus tours will run each weekend for six weeks, starting this Saturday.
People need to pre-book a seat on the tour by calling the Canterbury Earthquake Recovery Authority's 0800 number.
The lines opened at 8am on Tuesday and the authority says they were overloaded within half an hour.
Apologising for the frustration, chief executive Roger Sutton says there will be opportunities for everyone to take part.