In its broadest aspect, the safety belt according to the invention is characterized in that the top end of the chest strap is connected, in a manner known per se, to a top mounting secured to the body or frame of the vehicle at a point substantially on a level with and substantially behind and on one side of the shoulder of the strapped person, that on either side of the seat of the vehicle a floor mounting is secured to the floor or the frame of the vehicle, that one end of the hip strap is connected tothe floor mounting which is located on the same side as the top mounting, and that the. chest strap and the hip strap form a continuous sling which is detachably connected to the other floor mounting. The chest strap may pass from the top mounting either over a shoulder or below the corresponding arm of the person. The length of the sling forming the chest strap and the hip strap is suitably adjustable.