Section 29006 Of Chapter 1. Towing Equipment From California Vehicle Code >> Division 13. >> Chapter 1.

. (a) No person shall operate a vehicle towing another motor vehicle upon a freeway unless the towing vehicle is coupled to the towed vehicle by a rigid structure attached securely to both vehicles by nonrigid means.
  (b) The requirements of subdivision (a) are not applicable to a vehicle towing a motor vehicle which has been disabled and is being towed from the point of disablement to the nearest and most accessible exit from the freeway.