A semi-automatic transmission, also known as paddle-shift gearbox, allows a driver to switch between manual and auto control on their transmission. They are often used is sportier trims of vehicles and do not make use of a clutch pedal as found in standard vehicles.
The 2015 Corvette Stingray makes use of a semi-automatic paddle shift system. The paddle-shift gearbox allows the Corvette to retain the comfort of an automatic transmission, while being able to offer the driver the capabilities of extremely fast shifts, according to Chevrolet.
The semi-automatic transmission use a special system of sensors, pneumatic systems and actuators to replace the clutch mechanism inside of a vehicle and switch into each gear. These type of systems are often used in motorcycles.