Hybrid Buses - Regenerative Braking

Metro Transity hybrid buses utilize a process called regenerative braking.
Forty percent of the energy to accelerate the bus is energy saved during regenerative braking. When stopping or decelerating, vehicle energy is converted to electric energy and stored. In effect, the motor becomes a generator.
An Allison Hybrid Electric Drive System can significantly out-accelerate a vehicle equipped with a conventional drivetrain or an alternative fuel system.