Designed with Safety as the Top Priority
At Proterra, “Safety First” is far more than a slogan; it has been a Proterra mantra since the company’s founding and something we consider in every aspect of our business. With this guiding principle, Proterraregistered
vehicles are engineered with passenger safety as a primary concern.
The Safest Battery Placement and Design
Safety begins with vehicle design. Battery packs in Proterra ZX5registered
transit buses are located in the safest possible location—outside of the passenger compartment, beneath the bus between the two axles. The batteries are liquid temperature-controlled and incorporate both active and passive safety systems, with ruggedized, reinforced battery enclosures that are further separated from passengers by a heavy-duty structural barrier.

Unparalleled Durability
Proterra manufactures one of the most durable electric transit vehicles in the industry. The ZX5 bus body is constructed with impact-absorbing, carbon-fiber-reinforced composite materials, which minimizes repairs and maintenance while maximizing vehicle longevity. Steel-body buses will experience significant fatigue and corrosion throughout their required 12-year lifespan, while the advanced carbon composite body of the ZX5 resists rust and can stay in continuous service for years longer, with an expected lifespan of up to 18 years.

Advanced Battery Testing
Proterra conducts the most rigorous testing and validation program in the industry for battery-electric transit vehicles. Watch how ZX5 vehicles and battery packs are tested for safety, durability, performance and reliability.
Advanced Vehicle Testing
To prove that the ZX5 carbon-fiber-reinforced composite body can withstand the toughest real world conditions, Proterra tested its durability and reliability in Troy, Michigan at the Exova Defiance Test Facility, one of the world’s leading facilities specializing in vibration, shock and multiple axis simulations. The test simulated 750,000 miles—equivalent to 18 years of on-the-road wear-and-tear. The results showed that no part of the bus body or other systems were compromised, including the chassis, battery packs and mounting, windows and doors. It also validated Proterra’s industry-leading bus body design and manufacturing processes that support unparalleled safety, quality and performance.