Bus Operator Barrier Design: Guidelines and Considerations (2024)
Chapter: Summary
SUMMARY
Bus Operator Barrier Design: Guidelines and Considerations
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. 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.” 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.
The risks to bus operator health and safety are not limited to physical and verbal assaults. Another important but more pernicious risk to bus operator health is viral and bacterial infection. The COVID-19 pandemic in 2020 and 2021 clearly demonstrated this risk to everyone, including bus operators. 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. Some agencies quickly adopted droplet barriers and soon recognized the challenges other transit agencies have been facing for some time after installing security barriers: 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. Among the challenges transit bus operators have faced is the change in temperature around the bus operator workstation caused by 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. 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.
Objective
The goal of TCRP Project C-25, “Bus Operator Barrier Design,” was to produce information for North American public transportation agencies, standards committees, and government and non-government policy-making organizations on designing, procuring, and installing bus operator barriers to prioritize the health and safety of essential operators and the public they serve.
Approach
The approach of the research was to survey the transit bus industry, collect reference materials on the designs of barriers and heavy low-floor transit buses, produce a summary of design criteria, and produce three concept barrier configurations that may mitigate the risks to transit bus operator safety and health. This research 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 findings are practical and can be applied by public transportation agencies of varying sizes, means, and operational parameters, the research considered retrofit barrier designs for aftermarket as well as new purchase integration of current and novel bus operator workstation designs. To meet the need to address current transit bus operator workstation designs, the research team developed two concept barriers within a recent-generation transit bus computer model provided by a major North American transit bus manufacturer. To meet the need to address future transit bus designs, the research team applied the novel solution provided by the Bus of the Future team that was awarded by the FTA to develop a bus operator workstation compartment that would meet bus driver health and safety needs. The compartment included a concept bus operator barrier that completely separates the bus operator workstation from the passenger area or the passenger front entryway (or both, depending on the bus model).
Design Criteria
Design criteria were collected from the following sources: APTA, the European Bus System of the Future (EBSF), the International Organization for Standardization (ISO), and TCRP. The criteria collection for bus operator barrier design built on a previous exercise of criteria collection produced in TCRP Report 185: Bus Operator Workstation Design for Improving Occupational Health and Safety. The collection of these criteria was applied in the selection of design variables that affect bus operator barriers. Criteria from other sources, such as military standard MIL-STD-1472G, SAE, Code of Federal Regulations Parts 37 and 38 (ADA), and the Federal Motor Vehicle Safety Standards (FMVSS), were also collected. On the basis of these criteria, a bus operator barrier requirement matrix was developed and organized by area or component and features of that component. The areas and components are as follows, and the matrix is available in Appendix A:
- Operator Workstation;
- Seat;
- Steering Wheel;
- Pedals;
- Farebox;
- Door Control (Passenger Entry);
- Bus Floor;
- Driver’s Area;
- Ventilation, Climate;
- Ventilation, Airflow;
- Driver Area Barrier;
- Modesty Panels;
- Driver-Side Window;
- Passenger Doors;
- ADA Wheelchair;
- General Safety;
- Side Windows;
- Bus Operator Barrier;
- Bus Operator Barrier, Door; and
- Mirror.
Key Findings
The research team at Virginia Tech Transportation Institute (VTTI) applied the information collected from the TCRP panel, guidelines, standards, previous research, and a survey to develop a target risk mitigation approach for the three bus barrier concepts. The designs (Figures S-1, S-2, and S-3) and estimated risk mitigation outcomes are provided.
Retrofit or Integrated Bus Barrier Design, Concept A
- Physical, Spitting, and Other Attacks: Concept A was estimated to provide high mitigation of direct physical contact by limiting reach by passengers; low mitigation of attack by shooting a weapon around the barrier; and low mitigation of spitting around or over the barrier.
- Air Quality: Concept A was estimated to provide no mitigation of coughing or sneezing risk and no mitigation of air quality risk.
Figure S-3. Concept C, design configuration of Bus of the Future integrated bus operator barrier.
- Temperature: Concept A was estimated to provide low mitigation of cold temperatures, as the barrier may reduce cold gusts through the passenger entryway door but not change temperature and humidity.
- ADA: Concept A was estimated to provide clearance for passengers with disabilities on the basis of the minimal dimensions for the ADA clearance box.
- Usability: Concept A was estimated to provide medium mitigation of risk to bus operator reach and repetition, as the door does not have to be moved at every stop for driving visibility, although it is operated manually. The bus operator may latch or release under normal operation to perform passenger service; the bus operator may also latch or release for emergency egress.
- Visibility: Concept A was estimated to provide high mitigation of obstruction and glare for visibility of exterior mirrors and interior passenger mirrors; however, obstruction and glare from the barrier may exist when the bus operator looks at the passenger front entry door.
Retrofit or Integrated Bus Barrier Design, Concept B
- Physical, Spitting, and Other Attacks: Concept B was estimated to eliminate direct physical attack by passenger reach, to provide medium mitigation of attack by shooting a weapon around the barrier, and to provide high mitigation of spitting, as passengers cannot lean around the barrier.
- Air Quality: The size of the barrier in Concept B was estimated to provide medium mitigation of coughing and sneezing risk. Concept B was estimated to provide medium mitigation of air quality risk, depending on implementation of additional partitions between front entry and passenger compartments to limit gaps and increase pressure on the front side of the barrier.
- Temperature: Concept B was estimated to provide medium mitigation of cold temperatures: the barrier may reduce cold gusts through the passenger entry door, but temperature and humidity would not change.
- ADA: Concept B was estimated to pass the clearance for passengers with disabilities on the basis of the minimal dimensions for the ADA clearance box.
- Usability: Concept B was estimated to be implemented with automatic operation that is based on the door state at the passenger front entry door and uses a pneumatically powered armature and electromagnetic latches at both positions for boarding and driving. A power override would allow the bus operator to perform passenger service under normal operation. The concept includes a physical hinge release for non-powered emergency egress.
- Visibility: Concept B was estimated to provide high mitigation of obstruction and glare risk for visibility of exterior mirrors and interior passenger mirrors caused by the barrier being latched open while the bus is being driven. This concept was also estimated to provide high mitigation of risk for obstruction and glare when the driver is looking at the passenger front entry door, as the barrier door is automatically latched open while the bus is in motion.
Novel Bus of the Future Integrated Bus Barrier Design, Concept C
- Physical, Spitting, and Other Attacks: Concept C was estimated to eliminate direct physical attack by creating a separate floor-to-ceiling bus operator workstation compartment. The concept may mitigate attack by shooting a weapon by conveying the appearance that attackers cannot access the workstation. The concept eliminates spitting attack.
- Air Quality: Concept C was estimated to eliminate coughing and sneezing risk by incorporating a separate bus operator workstation compartment. The concept was estimated to provide high mitigation of air quality risk, assuming positive pressure can be created on the bus operator side.
- Temperature: Concept C was estimated to eliminate cold temperature risk. The risk of hot temperatures and humidity may not be mitigated and may be increased by the separate compartment, as a separate bus operator workstation HVAC system will be needed.
- ADA: Concept C was estimated not to pass clearance for passengers with disabilities on the basis of the minimal dimensions for the ADA clearance in the passenger front entryway. Concept C passes clearance for passengers with disabilities on the basis of the dimensions for the ADA clearance box in the mid/rear door entry.
- Usability: Concept C was estimated to be implemented with automatic operation based on the state of the passenger front entryway door and using a pneumatically powered armature and electromagnetic latches at both positions for boarding and driving.
- Visibility: Concept C was estimated to provide high mitigation of obstruction and glare risk for visibility of the curbside exterior mirror because the orientation of the stationary barrier does not interfere with the bus operator’s view. Another alternative that may provide high mitigation of risk for obstruction and glare over exterior mirrors is the use of cameras and displays to replace rearview mirrors. Additional defrosting/defogging vents near the additional barrier door and barrier stationary glazing surfaces may be needed to prevent obstructed vision caused by glass fogging.
