Bus Operator Barrier Design: Guidelines and Considerations (2024)
Chapter: 1 Introduction
CHAPTER 1
Introduction
The nation was reminded of the importance of security barriers for transit bus operators by the fatal attack in Florida on a Hillsborough Area Regional Transit Authority (HART) bus operator on May 18, 2019. The need for security barriers was reinforced by a serious attack on another HART bus operator later that same year. While these are two extreme examples, they are likely not unique, as assaults against transit workers have been underreported in the past. TCRP Synthesis 93: Practices to Protect Bus Operators from Passenger Assault defines assault broadly to include overt physical and verbal acts by a passenger that interfere with the transit worker’s ability to complete their scheduled run or other duties safely or that adversely affect the safety of the transit employee and customers (1). As stated in Transit Advisory Committee for Safety Report 14-01, “the vast majority of assaults against transit workers are non-fatal: 81% of assaults against bus operators are verbal and 60% involve spitting at the worker, while 2% involve weapons.” (2) Many of these assaults go unreported and do not lead to arrest, yet they still have a strong psychological impact on bus operators. A secure barrier that eliminates physical contact or reduces the fear of assault could significantly improve the lives and job satisfaction of bus operators, allowing them to focus on customer service and safe vehicle operation.
Another important but more pernicious risk to bus operator health is viral and bacterial infection. The COVID-19 pandemic in 2020 and 2021 taught the world that viral infections can easily turn into widespread events with significant consequences to everyone’s lives. A pandemic can disrupt essential services, such as public transit, a critical service that keeps people moving, including between medical facilities and health support systems. As reported in the October 6, 2020, editorial of Issues in Science and Technology, “COVID-19 Revealed an Invisible Hazard on American Buses,” more than 10,000 transit workers in the United States contracted COVID-19, and 89 members of the Amalgamated Transit Union died during the preceding 8 months (3).
Transit buses provide a convenient and predictable mode of transportation for members of the public, who can choose, on the basis of perceived risk, to enter and exit the bus at or between the many street stops. However, bus operators must remain in the same air space for much of their workday, regardless of whether an infected person is on board. Furthermore, the bus operator workstations in U.S. buses are designed to obtain heat and cooling primarily from the passenger HVAC system, for which the intake is located either in the rear of the bus or above the rider area. For this reason, new ventilation solutions that separate and filter the air for bus operators are needed for transit buses.
The Virginia Tech Transportation Institute (VTTI) completed an FTA/Center for Urban Transportation Research investigation into transit bus ventilation, finding that the driver window is the lowest point of pressure when the vehicle is in motion. Simply opening the operator-side window can increase the exposure of the bus operator to air from the passenger seating area (4, 5). VTTI also found that HVAC-equipped transit buses do not commonly include an option for a mixture of fresh air in the bus operator windshield defrost system or in the passenger HVAC system.
Although this study generated recommendations for simple, temporary solutions for multiple HVAC configurations, it is vital that other long-term solutions be explored.
Early in the COVID-19 pandemic, droplet transmission through exhaled air, rather than surface contact, was identified as the primary path of virus transmission. Airborne transmission via small droplets and particles that can linger in the air was later recognized as well (6). On the basis of guidance from the Centers for Disease Control and Prevention (CDC) regarding risks for transmission, many transit agencies limited all bus passenger entry to the rear door until a barrier could be installed to reduce the direct transfer of large droplets between passengers and operators. Early adopters of these droplet barriers recognized the challenges that other transit agencies have faced after installation: a barrier mounted between the bus operator and the curbside of the bus can limit visibility inside and outside the vehicle, making it difficult to view passengers in the rear and creating glare on the barrier surface between the bus operator and the curbside rearview mirror.
Accordingly, transit agencies adopted barriers with manually sliding sections, requiring the bus operator to close the barrier before opening the front door at every stop and to reopen it before departing. When considering the CDC hierarchy of risk control, this requirement turned a promising engineering control into an administrative control that requires bus operators to remember to close the barrier to protect themselves. Agencies that chose to adopt barriers providing automated security and droplet protection recognized the added challenge of securing the barrier. That is, egress and functional release options were needed to allow operators to open the barrier door in an emergency or when assisting persons with mobility impairments and disabilities.
Among the challenges transit bus operators have faced is that the open layout of the front of the bus and the frequent need for the front entry door to be opened for passenger boarding and deboarding causes changes in temperature around the bus operator workstation. Features have been added over the years to improve climate and HVAC controls for bus operators. In cold climates and seasons, bus operators have the option to use heating units to support windshield, driver, and curbside defogging and defrosting to increase the temperature in the bus operator workstation and reduce cold stress. However, in hot and humid conditions, bus operators rely on the primary bus passenger HVAC, which is often sourced from the interior and back of the bus through overhead ducts, to provide air conditioning and cool the bus operator workstation. Some transit buses are equipped with additional overhead HVAC booster fans to increase the volume of air pulled from the primary bus HVAC through the overhead ducts. Some buses are also equipped with dash-mounted fans to assist with defogging of windows, which bus operators also use to assist in cooling their workstations.
These risks to bus operator security, health, comfort, and driving visibility, as well as the high repetition of transit bus tasks, need to be considered when determining how to design a bus operator barrier. To address these risks, the objective of this research was to provide practical information for public transportation agencies on designing, procuring, and installing bus operator barriers to prioritize the health and safety of essential operators and the public they serve. This information was developed to consider assault prevention, air quality and ventilation, and thermal conditions; bus operator visibility, protection, security, safety, health, mobility, and comfort; ADA compliance for bus access and mobility; and emergency egress. To ensure the information is practical and can be applied by public transportation agencies of varying sizes, means, and operational parameters, the research considered both retrofit barrier designs for aftermarket or new purchase integration and novel bus operator workstation designs.
