Bobtail protection is comparable - it insures the truck whilst "bobtailing", this means operating with no trailer connected. So if you crash the tractor whilst bobtailing to receive repairs, Bobtail insurance pays for harm and injuries. However not required, NTL and Bobtail policies present inexpensive liability security for California truckers https://www.amazon.com.au/gp/product/B0D4MRHZL9