CHAPTER 3

Findings

Survey Results

The data captured with this survey were intended to inform the transit industry and its stakeholders about the current use of bus operator barriers and to inform future guidelines and barrier designs, including the bus operator barriers being designed as part of this project. Survey respondents were not required to answer all questions. Respondents may have chosen to skip certain questions because they lacked data or knowledge on that topic, and some questions directed the respondents to skip questions based on their responses to another question. In those cases, there were fewer total responses per question than the total number of respondents who started the survey.

Survey Demographics

A total of 77 respondents submitted survey results from across North America. The survey was distributed from fall 2022 through winter 2023. Forty-nine (49) respondents identified their organization or agency affiliation. Seven respondents left the question field empty and did not identify their affiliation. Other respondents skipped this question. Out of the 49 who identified, two of the survey respondents were from Canada, while the other 47 were from across the United States. Table 3 provides a list of transit agencies and organizations represented in the survey.

Survey respondents were asked to provide their current job title, role, and position at their transit agency of employment. Job roles were broken into four basic categories with each category having different job titles or positions for respondents to choose from. The four basic job role categories were

• Administration, Upper Management, and Executive Leadership (Agency Level);
• Maintenance Operations (Depot, Division, Department Level);
• Transportation Operations (Depot, Division, Department Level); and
• Engineering, Procurement, and Non-operations (Agency Level).

Figure 15 provides the breakdown of the 77 survey respondents by job title, role, or position within their respective transit agencies.

Across 53 survey respondents, the average years of experience in their current job title, role, or position was 9.7, with a high of 34 years and a low of 1 year. Table 4 breaks out average years of experience by job category. Additionally, among 45 survey respondents, 11 (24%) identified as being a union representative.

Table 3. Transit agencies completing bus operator barrier survey (n = 56).

Table 4. Average years of experience by job category (n = 53).

Agency Barrier Use

The next set of survey questions captured overall use of bus operator barriers, the main purpose of the bus operator barrier for each transit agency, and whether barrier use would continue as the COVID-19 pandemic wanes.

The results among 54 respondents showed that 52 (96%) of these respondents indicated their transit agency was currently using bus operator barriers. Among 51 respondents, only 16 (31%) indicated their transit agency was using bus operator barriers before the COVID-19 pandemic. As a follow-up question for transit agencies using bus operator barriers before the COVID-19 pandemic, these respondents were asked to identify the primary reason for their use. Table 5 provides a breakdown of bus operator barrier use factors among 16 respondents.

Among respondents indicating their transit agency did not use bus operator barriers before the COVID-19 pandemic, all 34 indicated their agency planned to continue using the bus operator barriers even as the COVID-19 pandemic wanes and restrictions are lifted.

Requirements may vary between transit agencies on required use of the bus operator barriers by their operators. To assess this requirement, survey respondents were asked to indicate whether bus operators were required to actively use the barrier during revenue-generating operations. A total of 50 respondents chose to answer this question, with 46 (92%) reporting they are required to actively use the bus operator barrier during revenue-generating runs, while four (8%) were not required to actively use the barrier.

Finally, for the four respondents who indicated their transit agency is not currently using bus operator barriers, three reported that their agency has either considered or is currently considering the use of bus operator barriers. The primary reasons respondents gave for why these agencies have not implemented bus operator barriers were

• No record of assaults,
• Concern for emergency evacuation of the operator, and
• Need for more research to determine the quality and effectiveness of barriers.

Barrier Design and Process

The survey requested information about the design elements of bus operator barriers currently in use, including selection and evaluation, redesign, continued use, ADA compliance, and

Table 5. Bus operator barrier use factors before COVID-19 pandemic (n = 16).

Costs

Respondents were asked to provide the initial cost of bus operator barriers, average yearly maintenance costs per bus operator barrier, average life cycle of the barriers, and whether the bus operator barriers were designed in house, by the bus manufacturer, or by a third-party vendor.

Twenty (20) respondents out of the 31 indicated they did not know or were unsure of the initial costs per bus operator barrier. Of the 11 respondents who provided a cost estimate, retrofit barrier costs ranged from $25 (i.e., shower curtain) to $7,000 per barrier, while factory-installed barriers on new buses ranged from $3,000 to $7,500 per barrier.

Respondents also provided information on the design of the bus operator barriers. Among the 33 responses received, eight (24%) reported the barriers were designed in house, 13 (39%) reported the barriers were designed by a third-party vendor, six (18%) reported the barriers were designed by some combination of both in-house and third-party technicians, and six (18%) reported being unsure.

The survey also sought information regarding the average yearly maintenance cost per bus operator barrier as well as the average life cycle of these barriers. Of the 29 respondents, 19 (66%) indicated they did not know the average yearly maintenance cost per barrier; however, 10 (34%) respondents reported average maintenance costs ranging from $0 to $1,000 per barrier per year. Similarly, for the average life cycle of bus operator barriers, 22 out of 30 respondents were unsure.

Table 6. Bus operator barrier maintenance cycle (n = 37).

Barrier Designs

Three bus operator barrier designs were developed on the basis of issues present in the North American transit bus industry today and the range of preferences and needs identified by the survey. The designs seek to address the risk mitigation targets defined in the approach. The three concept designs are illustrated in this section.

As demonstrated in Figure 21, Concept A was based on an existing bus operator barrier design framework used today in New York City (see the section on previous research). Data collected from multiple bus and barrier configurations were considered in this design. Concept A was modeled in an existing battery electric low-floor transit bus provided by Gillig LLC to demonstrate the size, scale, and feasibility of the concept in a current production bus. This barrier concept was not developed by Gillig LLC and cannot be considered a final assembly that could be immediately manufactured or installed in any specific bus configuration.

As demonstrated in Figure 22, Concept B was based on a novel idea to maximize the barrier size between the bus operator and the passenger front entryway with the intention that the bus barrier door would move with the front entry door at every stop. The transparent glazing would provide the bus operator protection while stopped and an unobstructed view while driving, after the passenger front entry door was closed. Concept B was modeled in an existing battery electric low-floor transit bus provided by Gillig LLC to demonstrate the size, scale, and feasibility of the concept in a current production bus. This barrier concept was not developed by Gillig LLC and is not to be considered a final assembly that could be immediately manufactured or installed in any specific bus configuration.

As demonstrated in Figure 23, Concept C was based on a novel barrier and bus body/chassis idea to completely separate the bus operator from the passenger front entryway and passenger compartment, with the intention that the bus barrier door would move automatically with the front entry door at every stop (like Concept B), provide protection for the bus operator while

Requirement Matrix Concept Status

Design criteria that pertain to bus operator barriers were organized according to component/area variables and feature variables as described in the section on design criteria. The full criteria list is provided in the requirement matrix in Appendix A. During the development of the bus operator barrier by the research team, these criteria were applied to guide the attributes of Concepts A and B. The design effort in the Bus of the Future project occurred before the collection of criteria for this project was complete. However, draft versions of the requirement matrix were shared with the Bus of the Future research team.

The application of the requirement matrix included two steps for each bus barrier concept. First, each criterion was evaluated against each concept. If a criterion applied to the concept (i.e., A, B, C) then that concept was identified with that criterion. For example, the feature variable “Glare, General” in the variable “Driver’s Area” references a criterion from APTA that the glare should be “minimize[d] to the extent possible.” This criterion applies to Concept A because even though glazing was designed to avoid interference from the bus operator’s vision with the curbside rearview exterior mirror, the glazing is fixed during bus driving and may interfere or collect glare over the view of the passenger front entry door used to see that side of the bus for driving. However, the Concept B bus operator barrier is intended to automatically adjust position to latch against the passenger compartment partition and will not interfere with the bus operator’s view of the mirror or passenger entry door. For this example, Concept C was also included as a priority for this criterion in case the bus operator chooses to keep the barrier door latched near the bus operator workstation, which could interfere with the bus operator’s view of the passenger entryway door and collect glare.

The second step in the application of the requirement matrix was to define the status or anticipated satisfaction of that criterion on the basis of the final design of each bus operator barrier concept. Using the same example, the status for the feature variable “Glare, General” for Concept A was, “Potential issue, material selection is crucial.” The status for this feature variable for Concept B was “Alleviated by closing [barrier door] to rear (open to driver) for driving.” The status for this feature variable for Concept C was “Barrier glazing can be lowered to reduce glaring. Glare from the barrier can be alleviated by closing to rear (open to driver). Fixed glazing is parallel to the line of sight to minimize obstruction. It should reach to vehicle ‘B’ post to ensure a direct view to the windshield and side window.” Status and descriptions for each criterion and concept bus operator barrier are provided in the requirement matrix for use by designers and implementers.

Risk Mitigation Evaluation

Each of the bus operator barrier concepts was evaluated against the target risk mitigation attributes. The findings of this evaluation are organized by concept and risk attribute.

Concept A Risk Mitigation

Physical, Spitting, and Other Attacks

As demonstrated in Figure 24, Concept A was estimated to provide high mitigation of direct physical contact by limiting reach by passengers, low mitigation of an attack by shooting a weapon around the barrier, and low mitigation of spitting around or over the barrier. Passengers may be able to reach around the door and release the operator-side latch.

Air Quality

As demonstrated in Figure 25, Concept A was estimated to provide no mitigation of coughing/sneezing risk and no mitigation of air quality risk.

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. The gap between the barrier and windshield may limit the potential benefit.

ADA

As demonstrated in Figure 26, Concept A was estimated to pass clearance for passengers with disabilities on the basis of the minimal dimensions for the ADA clearance box. This concept maintains the current common configuration for the front entry ramp.

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. The barrier door

Air Quality

As demonstrated in Figure 29, the size of the Concept B barrier was estimated to provide medium mitigation of coughing/sneezing risk. It 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. The targeted gaps of 1 in. were not achieved without modifications and additions to the passenger compartment partition. The pressure differential is also dependent on the use of external bus openings (e.g., windows and hatches) that may reduce potential airflow benefits. Filtered fresh air inlets in the bus HVAC, defrosting system, or bus operator workstation may increase these potential benefits by mixing fresh air with internal air.

Temperature

Concept B was estimated to provide medium mitigation of cold temperatures. The barrier may reduce cold gusts through the passenger entry door, but there would be no change to temperature and humidity. The extended length of the barrier toward the windshield may increase the potential benefit compared with Concept A.

ADA

As demonstrated in Figure 30, Concept B was estimated to pass the clearance for passengers with disabilities on the basis of the minimal dimensions for the ADA clearance box. The concept maintains the current common configuration for a front entry ramp.

Usability

As demonstrated in Figure 31, Concept B was estimated to be implemented with automatic operation based on passenger front entry door state and using a powered pneumatic armature and electromagnetic latches (Figure 32) 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

As demonstrated in Figure 33, Concept B was estimated to provide high mitigation of obstruction/glare risk for visibility of exterior mirrors and interior passenger mirrors because the barrier latching position is open when the bus is in motion. This concept was also estimated to provide high mitigation of risk for obstruction/glare when an operator is looking at the passenger front entry door, as the barrier door automatically latches open while driving.

Concept C Risk Mitigation

Physical, Spitting, and Other Attacks

As demonstrated in Figure 34, Concept C was estimated to eliminate direct physical attack by creating a separate floor-to-ceiling bus operator workstation compartment. The concept may convey the appearance that attackers cannot access the workstation, potentially mitigating attack by shooting a weapon. The concept eliminates spitting attack. The door release would not be accessible by passengers.

Air Quality

As demonstrated in Figure 35, Concept C was estimated to eliminate coughing/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 workstation side.

Temperature

Concept C was estimated to eliminate cold temperature risk. The risk caused by hot temperatures and humidity may not be mitigated and may be increased because the separate compartment creates the need for a separate bus operator workstation HVAC system and additional defrosting/defogging vents near the additional barrier door and barrier stationary glazing surfaces.

ADA

Concept C was estimated not to pass clearance for passengers with disabilities on the basis of the minimal dimensions for ADA clearance in the passenger front entryway. The existing bus architecture used by the Bus of the Future team was not designed for ADA passenger front door entry. However, 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, as seen in Figure 36. Assuming the bus can dock for mid-entry and the bus would be equipped with a mid-entry ramp, this approach could accommodate devices that exceed the minimum ADA clearance box today.

Usability

As demonstrated in Figure 37, Concept C was estimated to be implemented with automatic operation based on the state of the passenger front entryway door, using a pneumatically powered armature and electromagnetic latches (Figure 38) at both positions for boarding and driving.

Concept C Operations Feedback

• The mechanical interface between the barrier and stationary transparent structure at the windshield end is not clear.
• Where is the farebox?
• Did this configuration consider visibility with the driver’s seat in full forward and aft positions?
• With a fully separate air/temperature supply, the designers should consider condensation on the bus operator barrier glass.
• Front door use may be limited to bus operators in future applications. Some passengers report a preference for boarding and disembarking at the rear doorway.

Concept B HVAC Manufacturer Feedback

• The main HVAC could be used with extra ducting to get at least 100 cubic feet per minute (cfm) to the driver for comfort with this design, allowing for air return and circulation.
• Testing may be required, but additional cooling for the driver could be accomplished with an in-duct damper.

Concept C HVAC Manufacturer Feedback

• A sealed cockpit will necessitate a method for depressurizing the enclosure to let in new conditioned air, meaning there will need to be some sort of return pathway.
• There may be an opportunity or need for a separate HVAC. This could be a stand-alone electric system or could be tied into the main HVAC.
• There may be a need to consider independent cooling and dehumidification for comfort; consider the effects of a well-sealed compartment with large amounts of glass.
• Consider that battery electric may require a glycol system for heat.
• Regarding air quality, consider the negative effects of some alternative air purifying solutions on passengers and interior components. Consider MERV-rated filters but be cautious about additional pressure on motors and remember regular maintenance.

General, Glazing Supplier Feedback

• Reflection on panels can be a major concern for implementing barriers on large fixed-route buses.
• Solutions to prevent glare are limited or non-existent for polycarbonate barrier materials, and therefore some larger agencies will use glass that offers some amount of anti-reflection but comes at a significant weight and expense.
• For operators of mid-size or smaller buses, using glass in barriers may not be recommended because the driver is sitting lower and the door may extend above their head.
• Following the FMVSS No. 205 standard is important for barrier strength and safety.
• For glazing to be bullet resistant it must be laminated, which would add significant weight to the door panel and would need to be part of a total redesign of the operator doors. Bullet resistance may be impractical on small to mid-size buses.

General, Bus Manufacturer Feedback

• It is important that implementers of bus operator barriers check compliance with ADA throughout the design process, from concept development to simulation to integration and installation, to make sure that the bus operator barrier does not interfere with handholds for ambulatory impaired passengers and that sufficient clearance is provided for passengers with mobility devices (e.g., wheelchairs).