If you are an in accident with property damage only, how do the insurance companies determine who is at fault if you both blame the other person?
Each insurance company will pay for the damage to its insured’s car, assuming each party hadscollision. The insurance companies then try to negotiate a settlement. It is unlikely that they reach a settlement. Why? Because an insurance adjuster will usually take the side of it’s insured. If the insurance companies are members of intercompany arbitration, then they send it there. (Basically, a panel of three insurance adjusters, none of whom work for the insurance companies involved, make a decision that is binding on the insurance companies.) If one company is not a member, then they may file suit. If the damage is not that much, they usually forget about it.
Of course, if one party does not have insurance, you want to read my archives about how insurance companies treat you and know your rights!
And, remember the insurance company can only consider it at fault if you are found 51% or more at fault. If they do consider it an at fault accident, they have to send you a letter telling you about your right to have them review it, and then the Department of Insurance review the liability finding.