A helmet safety system comprises a first set of sensors coupled to a helmet, a second set of sensors coupled to a vehicle, and one or more microcontrollers coupled to the first and second sets of sensors. The one or more microcontrollers can receive sensor data from the first and second sets of sensors and determine, based on the sensor data, that a user is using the bicycle but not wearing the helmet. Responsive to determining that the user is using the bicycle without wearing the helmet, the one or more microcontrollers perform remedial actions, such as disabling or limiting a functionality of the bicycle, emitting an alarm or alert, sending a notification to a first device of the user reminding the user to wear the helmet, and sending a notification to a second device indicating that the user is using the bicycle without wearing the helmet.