Speed controller for vehicles

A vehicle speed controlling system controlling speed of a vehicle, travelling along a road surface, said vehicle speed controlling system being active when said vehicle is on, said vehicle speed controlling system comprising:

• a. at least one controller;
• b. at least i) one throttle sensor for a non-electric vehicle or ii) one accelerator sensor for an electric vehicle, in communication with said at least one controller;
• c. at least one brake sensor in communication with said at least one controller;
• d. at least one vehicle speed sensor in communication with said at least one controller, wherein said at least one controller further comprises a PID controller;
• and
• e. at least one retardive braking system in communication with said at least one controller, wherein said at least one controller receives signals from said at least i) one throttle sensor for said non-electric vehicle or ii) one accelerator sensor for said electric vehicle, said at least one vehicle speed sensor and said at least one brake sensor and sends a signal to said at least one retardive braking system controlling speed of said vehicle based on factors including:
• i) maximum allowable vehicle speed limit value;
• ii) gross vehicle weight (Wv);
• iii) maximum angle of decline of said road surface θ;
• iv) radius of a static loaded tire of said vehicle (IT);
• v) deceleration factor (Fd), a value of how aggressively the vehicle speed should decrease;
• and
• vi) one of:
• overall gear ratio between a motor of said vehicle and a wheel assembly of said vehicle (RG) for said electric vehicle, or overall gear ratio between a retarder and drive wheels linked to a tractive device for said non-electric vehicle;
• wherein a maximum retardive torque is defined as TB=[rT×Wv×(Fd+sinθ)]/RG.