CHAPTER 2
Identify Needed ZEV Skills

This chapter examines the skills needed by the workforce that operates and maintains ZEVs. As the initial step of the skills-building process, transit agencies should identify the skill requirements. Resources and approaches that are provided later in this chapter include a list of transit-specific ZEV skills that were developed by a group of subject-matter experts representing both transit agencies and transit labor unions and that were facilitated and published by APTA.

Specialized training is needed for employees to operate and maintain ZEVs. Understanding the technology used in these vehicles is a first step in identifying the skills required for ZEV maintenance and operation. The literature establishes that ZEV maintenance tasks and associated training needs differ significantly from those associated with ICEs. That said, some transit employees may already have relevant skills, including those involved in working with high-voltage (HV) systems found on hybrid-electric buses and with gaseous fuel storage found on compressed natural gas (CNG) buses, as documented in an FTA case study on FCB deployment at Stark Area Regional Transit Authority (SARTA) in Canton, Ohio.²⁶

Although the public transit workforce will benefit from additional training, most transit agencies do not report that lack of training is affecting their ability to put ZEVs into service. Figure 5 shows that 9% of transit agencies are unable to put any of their ZEVs into service because their workforce is not trained. It must be noted, however, that many of these vehicles are still covered under warranty, so OEMs typically make needed repairs.

Generally, ZEVs are thought to require less maintenance than ICE-powered vehicles because of factors such as having fewer moving components and experiencing reduced brake wear due to regenerative braking.²⁷ However, tire wear may be greater for electric vehicles (EVs) because of their extra weight.²⁸ While ZEV batteries may require less maintenance in normal operating conditions, additional electrical diagnostic and safety skills and job tasks are required in light of the high-voltage nature of the propulsion.²⁹ So-called teething problems associated with the introduction of new ZEV technology may generate additional maintenance and repair activity.³⁰

Diagnostic Skills Training

While ZEV maintenance requirements may be reduced, diagnostic requirements have increased significantly.³¹ The ability to analyze telemetry data using sophisticated tools and equipment is essential to repairing faults in these vehicles and keeping them in operation. The workforce may see a delineation between qualified workers where, based on skill set and training, some may only perform regular maintenance tasks, and others focus on the diagnostics and high-voltage–related activities as specialists. This research also shows that there is some transfer of skills between those working on traditional diesel vehicles and ZEVs:

N = 63. Source: TCRP Project J-11/Task 46 industry survey, summer 2024.

Long Description.

The data shows yes, we are unable to put any ZEVs in service 9 percent; yes, we are unable to put some ZEVs in service, 13 percent; Yes, we are unable to put ZEVs in for a full day of service (additional vehicle to operate full span of service), 22 percent; and No, we are able to put all of our ZEVs in service, 56 percent.

• The industry survey indicated that most respondents (67%) feel that skills are “somewhat transferable” between diesel and ZEV systems, while zero respondents answered “transferable,” 11% answered that skills are “not transferable at all,” and 22% answered “very transferable.”
• Focus group participants highlighted that there is greater transfer of skills between hybrid vehicles and ZEVs. For some transit agencies, whether intentionally or coincidentally, hybrids served as a stepping stone between diesel and ZEV systems.

Safety Training for ZEVs

Safety is always a critical concern of transit agencies. Publicized incidents of lithium battery fires may affect the comfort level of transit agency workers tasked with working on and around ZEVs, and adequate training is necessary to prevent and mitigate the risks of both types of propulsion discussed in the following bullet points:

• Electric vehicles have HV electrical systems that typically range from 400 to 1,000 volts,³² presenting additional safety concerns when compared to conventional transit buses with 12- and 24-volt electrical systems, which creates a need for safety equipment and training.
• Hydrogen vehicles also have properties that elevate safety concerns and require special training and attention. Hydrogen fuel is stored under high pressure and extremely low temperature, has no odor, and cannot have an odorant added. It burns invisibly with no smoke, and large hydrogen fires can only be stopped by turning off the fuel supply.

TCRP Research Report 219: Guidebook for Deploying Zero-Emission Transit Buses recommends conducting a hazard and operability study to identify risks and make sure that appropriate safety systems are in place.³³ Many OEMs, especially those associated with electric automobiles and trucks, with some limited bus examples, have produced emergency response guides for ZEV safety incidents that are available on the National Highway Traffic Safety Administration (NHTSA) website.³⁴

• Fire suppression. In addition to training transit workers to safely maintain HV components and hydrogen storage and risk mitigation equipment, training around fire suppression and effective coordination with first responders and firefighters is crucial.³⁵ Both lithium-ion batteries and hydrogen fuel have unique properties that create challenges for fire mitigation and suppression, not only for first responders but for the transit workforce as well. The batteries in battery-electric vehicles, due to heating, damage, or overcharging, can experience thermal runaway, in which chemical reactions in the batteryʼs cells cause rapid heating with insufficient heat dissipation.
• Thermal events. In addition to fire, thermal events can cause the release of toxic gases, explosions, and secondary fires in adjacent cells or batteries. Fires caused by lithium-ion batteries burn at very high heat. As of this writing, there are no known procedures that are completely effective at putting out electric vehicle (EV) battery–related fires. The current process is to control them and let them burn themselves out.
• Damaged batteries also carry the risk of electric shock for maintenance workers and first responders.³⁶ Hydrogen is highly flammable and burns rapidly at high heat. Leaks that result in pooling of hydrogen produce the greatest risk.³⁷

Aware of the risks, TCRP has initiated a project on the development of a guide to lithium-ion battery transit bus fire prevention and risk management with recommended practices for original equipment manufacturers, battery companies, transit agency facilities, and vehicle maintenance.³⁸

Common protocols involve safe parking and spacing of buses, isolation of buses experiencing thermal events, and coordination with fire safety personnel.³⁹ Transit agencies have hosted on-site training with first responders and fire departments in their service area.⁴⁰ The National Renewable Energy Laboratory (NREL), an institution funded by the U.S. Department of Energy to perform clean energy research, development, and deployment,⁴¹ has held three listening sessions with its Electric Transit User Group (one in 2022 and two in 2024) to hear from industry stakeholders about their experiences deploying battery-electric and fuel-cell vehicles. While the notes from these meetings do not indicate that workforce challenges were a focus, they do reference concerns that relate to safety.

One issue that transit agencies face is limited space in bus facilities. While safety best practices for battery-electric vehicles include adequate spacing between parked vehicles, transit agencies may have constraints on available space.⁴² This creates a greater need for adequate maintenance and safety training to minimize and mitigate thermal events.

Because of the safety concerns of working on or near electric vehicles, there must be a greater emphasis on safety training. The Occupational Safety and Health Administration (OSHA) discusses an electrical employee being “qualified” in OSHA standards 1910.332(a) and 1910.332(b)(3). If employees perform electrical work of any type, they need to be qualified, and the qualifying agent is the employer, which places additional requirements on transit agencies. The National Fire Protection Association (NFPA) created 70E: Standard for Electrical Safety in the Workplace to help employers meet the performance requirements of the OSHA standards for electrical safety.⁴³ While NFPA 70E training is not required by law, meeting OSHA requirements for electrical safety training is.

OEMs and industry stakeholders mentioned in focus groups that safety training is needed for all transit agency employees who come in contact with ZEVs. Following the protocol to maintain a safe working environment can become rote over time, and workers may start to rush through processes and safety checks. For this reason, ongoing refresher training on ZEV safety is critical to underscore the importance of safe operations and maintenance practices and to ensure a safe working environment.

Approaches and Resources

This section provides several approaches to consider and resources to use as transit agencies work to build ZEV skills.

Skills Identified in APTAʼs Zero-Emission Bus Maintenance Training Recommended Practice

The International Transportation Learning Center (ITLC) collaborated with APTA to develop Zero-Emission Bus Maintenance Training: Recommended Practice, issued in 2023. This recommended practice (RP) provides guidance for developing ZEB maintenance training curricula and materials. It includes a series of learning objectives that represent the knowledge and skills technicians should acquire as a result of ZEB training.⁴⁴ The RP is divided into three levels:

• Level 100 identifies the knowledge and skills technicians need to gain a basic understanding of how ZEBs operate, how they compare and contrast with other types of buses, general safety precautions, and the function of each major component.
• Level 200 expands the previous module by providing more detailed information on ZEB safety, components, systems, and theory of operation.
• Level 300 focuses on ZEB troubleshooting techniques, related special tools, and the knowledge and skills that technicians need to perform common ZEB maintenance and repair tasks. ⁴⁵

Level 400, overhaul and rebuilding procedures, will be added when additional ZEV experience is gained. Learning objectives contained in the RP serve as a checklist for any developer of ZEV training materials, ensuring that all pertinent information is included. The guidelines can also be modified to accommodate specific equipment or special transit agency conditions. The RP was developed on a joint labor–management basis with subject-matter experts from a variety of positions, including maintenance managers, instructors, and technicians.

The RP also includes a section on safety training that identifies HV systems and their associated risks, hardware, onboard safety equipment, and required personal protective equipment (PPE),⁴⁶ indicating that safety is particularly important when handling ZEBs. In addition to understanding the HV system, ZEB technicians must know how to conduct routine maintenance and testing of critical safety systems, such as hydrogen sensors and ground-fault detection.⁴⁷

Transit agencies should consider including compliance with the APTA RP when developing their own ZEV training materials, when purchasing ZEV training in the vehicle procurement process, or when specifying ZEV training from a third-party vendor or training institution.⁴⁸ IndyGo has used the RP to validate the training program developed by the OEM and adopted for use by the internal training department.

Electrified Transportation Pro+ Training and Certification Program

Another resource for identifying the skills needed to maintain and repair ZEBs is the Electrified Transportation Pro+ Training and Certification program developed in part with the Society of Automotive Engineers for electric vehicles as a way to provide a path to certification. Skills include the ability to demonstrate the general sequential steps in disabling a high-voltage system on a live vehicle and how to identify components of a powertrain transmission or drive unit system.^49,50