Extraboard Management

In the transit industry scheduled service delivery is organized around the assignment of vehicles and operators. These regular service assignments are typically made for three-month periods. In daily operations, however, scheduled operator assignments can open up as a result of absences, quits and retirements, promotions, in-service training, approved leaves, and personal days off. These daily open assignments are filled from a reserve pool known as extraboard operators. The proposed research intends to examine the planning and daily management of the extraboard at TriMet, the transit provider for the Portland, Oregon metropolitan area. The number of open assignments can vary substantially…

In the transit industry scheduled service delivery is organized around the assignment of vehicles and operators.  These regular service assignments are typically made for three-month periods.  In daily operations, however, scheduled operator assignments can open up as a result of absences, quits and retirements, promotions, in-service training, approved leaves, and personal days off.  These daily open assignments are filled from a reserve pool known as extraboard operators.  The proposed research intends to examine the planning and daily management of the extraboard at TriMet, the transit provider for the Portland, Oregon metropolitan area.

The number of open assignments can vary substantially from day to day.  On some days, openings are smaller than the available extraboard pool, leaving some operators on standby status.  In 2008, extraboard operator standby hours amounted to 3.5% of total scheduled run hours at TriMet.  Standby hours represent stranded costs in that they are paid with no service delivery provided in return.  On other days, openings exceed the available extraboard pool.  When this occurs, operations managers attempt to fill the surplus work by spot-assigning regular operators who are willing to work overtime.  Unscheduled overtime associated with these fills amounted to 3% of total operator costs at TriMet in 2008.  When available extraboard operators and operators willing to work overtime is less than the amount of open work, “miss-outs” occur and customers’ travel is disrupted.

The overall cost of maintaining extraboard operations at TriMet, at about 20% of total operator costs, is not trivial.  Like most mid and large-scale properties, TriMet uses sophisticated software for scheduling and runcutting regular scheduled service to minimize operating costs.  With the extraboard, however, the agency relies on historic practice and judgment, an approach that is common in the transit industry (DeAnnuntis and Morris, 2008).  Thus there is a potential to realize savings from closer examination of extraboard management practices.

The proposed research will examine daily patterns of open work and extraboard management for bus operations at TriMet.  It will address three general questions:

1) How much open work must be filled, and to what extent does the amount of open work vary systematically by day, month, and garage?
2) How efficient are the open work “fills” through extraboard and unscheduled overtime assignments?
3) What are the manpower implications of reducing or minimizing “miss-outs?”