Seat Belt Reminder

The Seat Belt Reminder (SBR) sensor mat detects occupants in passenger and rear seats. A seat belt reminder system in the vehicle triggers a warning light and/or an audible chime reminding unbuckled seat occupants to fasten their seat belts.
Seat belt reminders are intelligent, visual and audible devices that detect whether seat belts are in use in various seating positions and give out increasingly urgent warning signals until the belts are used.
Seat belt reminders should target part-time users, i.e. people who understand the value of a seat belt but sometimes do not use it.
They should not affect the drive ability of the vehicle.
A combination of visual and sound signals should be used.
The reminder signal should use multiple steps, i.e. build up progressively.