Taylor, Brian, Karen Frick and Martin Wachs (2008), "Contracting for Public Transit Services in the US", Privatisation and Regulation of Urban Transit Systems, Transport Research Centre Round Table 141: 47-62.</ref>
This may include utilizing more flexible non-union labor such as in split shifts. Split shifts are shifts in which a worker logs two four-hour shifts in the same day rather than a continuous shift of eight hours or more. This model fits well with peak hour travel in which operators are needed in the morning and afternoon but not necessarily in the middle of the day. Split shifts avoid overtime pay.