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Transportation Research Record 746 39 Systematic Procedure for Analysis of Bus Garage Locations Frank Spielberg and Marvin Golenberg The overhead costs of transit operations represent one area in which $1 million/year. Given the size of the potential sav­ economies can be achieved. For a large system the costs of putting buses ing, the investment in location studies can yield a on routes and pulling them off (pull-on and pull-off) and driver relief can high rate of return for any transit operator who is be substantial: up to 10 percent of the operating budget for the system considering a new facility. studied. These costs are directly related to the route structure and the Throughout the discussion that follows it must be location and capacity of bus garages. This paper describes a procedure that uses generally available planning data in the analysis of the pull-on remembered that the costs involved represent only one and pull-off and relief costs for alternative garage programs. Factors element in the evaluation of garage location. Other studied include the number of facilities, their location, their capacity, and elements include availability and cost of land, sur­ the routes served from each garage. It is shown that the location of rounding development, access streets, and environ­ garages in relation to day-base routes is a determinant of relief costs and mental impacts. All factors must be weighed in the that the difference in operating costs for alternative programs can ap­ selection of the location for a new facility. proach $1 million per year. COST ELEMENTS Operation of a transit system involves direct costs as­ sociated with the provision of revenue service and over­ Pull-on and pull-off costs are defined to include the head costs associated with system management. Reve­ vehicle kilometers and driver hours from the time the nue service operations have been studied extensively. bus leaves the garage until it enters revenue service Transit operators and planning agencies devote con­ and the same items from the time the bus leaves tinuous effort to determination of how to serve the cur­ revenue service until it returns to the garage. A rent and potential transit market with the proper alloca­ simplification introduced in the analysis method is the tion of bus kilometers and bus hours. assumption that a vehicle will enter or leave revenue Overhead costs, which consist of management, service only at a line terminal. Some properties will maintenance, planning, marketing, research, fringe carry passengers on trips to and from a garage; how­ benefits, and nonrevenue vehicle operation, are a daily ever, such trips are often lightly patronized as they concern of transit operators but have not been studied do not serve corridors of demand and can result in by the planning profession. A recent study by SG As­ longer or slower travel. Pull-on and pull-off costs are sociates, Inc., addressed two elements of overhead a subset of deadhead costs, which may also include costs as part of an analysis of the efficiency of alterna­ operations required by interlining. tive garage size and location alternatives: Driver relief, for this analysis, is defined as the number of pay hours required for a driver to travel 1. The costs of putting buses on routes and pulling from the garage to the relief point. The actual method them off (pull-on and pull-off costs) and of computing these pay hours will vary with the labor 2. The costs of driver relief. agreement of each property. For the system for which the method was developed, the pay hours are based on In the course of this study a procedure was developed the time required for the driver to travel from the for the planning analysis of alternative garage locations. sign-in location (the garage) to the relief point by use This paper describes the procedure. of the transit system. Thus, relief hours were a Overhead costs represent a significant portion of function not only of garage location but also of the route transit ope1·atingbudgets. Many elements can be structure and the operating headways at the time the addressed through management practice (e.g., adminis­ relief was scheduled (typically the day base). tration, maintenance, and policy) and can be quickly In many instances, relief costs, which were more modified if found to be inefficient. Other costs are than one-half of the amount of the pull-on and pull-off mandated by union contracts (e.g., reporting time, costs for all routes other than those that operate a wash-up time, meal breaks, fringe benefits, percentage peak-only service, were quite high because the only of straight runs, spread time penalties, and overtime· base-day service that operated near the garage offered payments). Management has less flexibility in changing infrequent service or because a transfer to a long head­ these provisions but can attempt modification, if ap­ way route was required. propl'iate, each time a new contract is negotiated. Two Only those relief costs that varied with garage loca­ cost elements, however, are a direct function of garage tion were considered; Invariant costs (e.g., time spent location-pull-on and pull-off and dl'iver-relief costs. waiting for the assigned vehicle, check-in, and wash-up) If a major facility is poorly located with respect to the are not included. current or future route structure, management may The basic structure of the problem is represented in have to accept added costs for many years. Figure 1. Figure 1 illustrates, in simplified form, the Relative to the total operating budget, the pull-on activity of a bus during the day. and pull-off and relief costs represent, for the system The bus leaves the garage in the morning and pro­ studied, roughly 10 percent of the annual operating ceeds to one route terminus (in this illustration, T1). budget. In absolute terms, they we1·e just wider The distance traveled from the garage to the point where $32 000/day. The difference among alternative garage the bus enters revenue service is the pull-on deadhead size and location strategies was about 10 percent in distance. For a large system that has extensive sub­ pull-on and pull-off and relief costs-about 1 percent urban routes, such as that studied, pull-on distances of the operating budget but an amount of more than can exceed25 km (15 miles) and require up to 1 hof travel 40 Transportation Research Record 746 Figure 1. Simplified illustration of daily bus operation. (GARAGE) ____J 1 -. ,------ \ ~~1 T, C::::====~======~===========T, A R2 "' Ill Ill I­ I­ :> :> 0 a: 0a: time. The vehicle operates on the route, as scheduled, nonproductive relief time. In fact, for a short route until it is time to return to the garage. The return to that is located a great distance from a garage, the the garage is the pull-off deadhead distance. Each travel time for drivers to the relief point can be a vehicle operated on a line will have at least one pull­ major cost item in route operations. on and one pull-off per day. Trippers, operated only A driver does not have to be dispatched from the as peak service, will pull-on and pull-off twice each garage for each relief on a line. Assume that route 1 day. In practice, a vehicle will often enter or leave operates on a 30-min headway. Driver A reports at revenue service from a point other than a terminal. 6:00 a.m., takes a vehicle, and enters service. Drivers For general planning purposes, this can be ignored, B, C, and D follow at 30-min intervals. After 4.5 h, as the productivity for such trips is typically low. A driver A must be relieved. Driver E travels to vehicle in revenue service from a garage to a suburban R2 and relieves driver A before 10:30 a.m. Driver A park-and-ride lot at 6:30 a.m. may not officially be takes a 30-min meal break at R2 and then relieves deadheading, but the effect is the same. driver B. The process continues until each driver is In actual operations the bus may not operate the relieved. same route all day; it may be interlined. Such sched­ Actually, coupling of pieces of work into drivers' uling can increase the efficiency of operations, but it runs may result in other patterns, but for planning introduces a complexity that cannot be treated at this purposes it can be assumed that the number of relief level of analysis. Further, since interlining operations drivers required per line will equal minimum meal will vary from schedule to schedule, consideration of break duration+ headway, rounded up to the next integer. such service options is not warranted when determining The number of relief movements (to or from the the sites for storage and maintenance facilities. garage) required is a function of One factor that can be accounted for is the maximum distance a bus can travel before it must return to the ga­ 1. Number of vehicles required to provide base rage to refuel-about 320 km (200 miles). If the operat­ service on the line, ing characteristics of the line are such that the first ve­ 2. Minimum break time, hicles out in the morning will exceed this service limit, 3. Maximum time permitted between breaks, and then either additional vehicles must be scheduled (with 4. Hours in the service day. additional pull-on and pull-off costs) or evening peak ve­ hicles, if available, are used for evening service.

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