TCRP F-04 [Completed]
Bus Operator Workstation Evaluation and Design Guidelines
| Project Data
||Pennsylvania Transportation Institute, The Pennsylvania State University |
Scientifically validated design guidelines for the bus operator workstation are provided that ergonomically accommodate bus operators ranging in size from the 5th percentile female to the 95th percentile male of the U.S. adult population. The design guidelines address all aspects of the bus operator workstation including the seat, steering assembly, pedals, instrument panels, farebox, and other equipment. While attempting to minimize the amount of required component adjustability to contain cost, adjustment is included in several key components including instrument panels, seat, and steering assembly. It is estimated that the workstation improvements identified in the design guidelines would increase the price of a standard transit bus by approximately $6,000, with a payback period of between 3.5 and 8 years based on direct cost savings associated with estimated reductions in bus operator injuries. Indirect cost savings such as the need for fewer replacement operators would further reduce this payback period.
The cost associated with bus operator injuries is a major concern of the transit industry. A significant portion of these injuries is associated with inadequate ergonomic design of the bus operator workstation. Injuries that can result from poor design or vibration include cumulative trauma disorders, soft tissue injuries, and musculoskeletal injuries. To reduce such injuries, bus operator workstations should be ergonomically compatible with the range of physical dimensions and functional capabilities of the bus operator population. The automotive and air transportation industries historically have placed a high priority on matching equipment to the dimensions and capabilities of the operator. In contrast, bus manufacturers are only recently, concurrent with requests from transit agencies, indicating the possibility of major design changes to the operator workstation.
Research was undertaken by the Pennsylvania Transportation Institute (PTI), Pennsylvania State University, to develop design guidelines for bus operator workstations using sound ergonomic/biomechanical principles to accommodate from the 5th percentile female to the 95th percentile male of the U.S. adult population and to validate the guidelines by testing a full-scale prototype of the workstation. The areas addressed in the research included the design and location of the operator seat, steering assembly, pedals, farebox, radio, transfer tray, public address system, sun visor, modesty panel, stanchions, controls, gauges, and other displays. The employment of control and display technology more advanced than technologies presently in use was encouraged as part of this research to enhance the safety, health, and comfort of bus operators.
To achieve the project objectives, the researchers first reviewed previous bus operator workstation design efforts and conducted a task analysis of bus operators to define how they interact with the workstation. A bus operator survey was then conducted to obtain recommendations from bus operators on the design and location of workstation elements. Approximately 140 bus operators responded to the survey, and this input was considered in the development of a workstation design concept. Based on this concept, a mock-up was constructed and evaluated by more than 100 individuals on the basis of several factors, including visibility, reach, and comfort. In addition, a workshop was held with representatives of bus manufacturers, bus operator workstation component manufacturers, and suppliers to obtain their important input into the design concept. A CAD-based analysis was then performed to validate the workstation design concept that had been developed. Through an iterative process, the workstation design guidelines were further refined. A prototype of the workstation was then constructed on a full-sized transit bus. The prototype was tested and evaluated with the assistance of 24 bus operators on PTI's closed-course test track. Each operator drove the prototype for approximately 2 hours, simulating various operating conditions. The driving schedule was similar to a typical transit service route. A video camera recorded various reaches and driving postures, and other instrumentation recorded vibration and operator force information. In addition, operators were asked for their personal evaluation of the workstation. At the conclusion of the prototype testing, final design guidelines were developed. These guidelines present the essential features that should be included in a workstation. Features include an 18-in. steering wheel, hanging pedals, and instrument panels divided into three areas according to function. Specific dimensional data is provided to facilitate the use of the guidelines in the specification and construction of future buses.
An executive summary of the bus operator workstation design gudelines has been published as TCRP Report No. 25, "Bus Operator Workstation Evaluation and Design Guidelines--Summary." An unpublished companion report, Bus Operator Workstation Evaluation and Design Guidelines-Final Report, provides the detailed technical validation for the guidelines and documents the entire research effort. This companion report is available on request from the TCRP and can also be viewed on the World Wide Web at: http://www.nap.edu/catalog.php?record_id=6343