Contracting transit operations
Transit agencies may contract for a portion or all of their operations needs. Smaller, newer transit agencies without historical relationships with unionized labor are more likely to contract all of their service. Larger, older agencies with standing relationships and long histories with unionized labor typically contract only a portion of their labor, if any at all. Reducing the number of union contracts would be politically difficult. 
Three general perceptions about how contracted labor reduces operating costs dominate contemporary views. First, contracting labor capitalizes on any difference in the cost of non-union labor in the private sector. Typically, non-union labor is believed to be less costly than unionized labor. Second, contracting with the private sector introduces competition into the labor market, creating an incentive for labor unions to reduce wages in their contracts with the public sector. Third, transit agencies contract out inefficient service in order to maintain efficient operations under their direct control.  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.
Contracted service is also seen as flexible over the long-term. Transit agencies view contracted labor as easier to initiate and terminate than directly hired labor. Rather than directly hiring workers for experimental routes, transit agencies may benefit from reduced political risk by contracting for service until the service is deemed to be permanent. Along these same lines, contracted labor is viewed as faster to initiate service than directly contracted labor. For new service routes, transit agencies may hire contracted operators in order to expedite start of service. 
- Iseki, Hiroyuki, Amy Ford and Rachel J. Factor (2006), “Contracting Practice in Fixed-Route Transit Service: Case Studies in California”, Transportation Research Record, 1927: 82-91.
- 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.