I assume ALI is liability insurance, which would cover another car/ person damaged/injured to a certain limited amount depending on the insurance. LDW would cover loss (theft) and CDW would cover collision damage to your rental car. They are sometimes bundled together. I assume your personal travel insurance gives you medical coverage in case you were injured. Am no insurance expert by any means, so please correct me if I'm mistaken. The $9 LDW would be per day so don't forget to calculate for 19 days and see if it includes CDW. Try to find out how much liability insurance would be per day also. Here is a site that explains the differences better than I could. Good luck