When it comes to public transportation, safety in motion is of the utmost concern; however, the transit commission in charge of a particular network of buses and trains must ensure that the facilities uphold standards in the instance of an emergency. The Hammer in Hand satisfies commuters' safety on both levels.
Shi Qiang's design is for a suspended handle that's attached to a strap and a rail below the ceiling of the carriage. Riders can clutch this handgrip while the vehicle is moving to prevent them from falling with the occasional quick stop or turn. Now, should a collision occur, people can pinch the sides of the Hammer in Hand to release it; they can grasp it like a mallet and use the metal-tipped corner as a means to break the windows.