Jack Ross, a minor, and his father, Albert Ross, were injured in 1989 when the vehicle in which they were traveling collided with a tractor-trailer operated by Malcolm Stephens and owned by Jack Kinard d/b/a Roy Bishop Housemovers (Kinard). Jack and his father, individually and as Jack’s next friend, filed a personal injury suit against Stephens and Kinard, a motor common carrier. See OCGA § 46-1-1 (9) (B). Appellee National Indemnity Company was joined in the action pursuant to OCGA § 46-7-12 (e) since it had issued a policy of motor carrier insurance to Kinard and had filed a certificate of insurance and a “Form F” policy endorsement with the Georgia Public Service Commission on Kinard’s behalf. However, the Kinard vehicle involved in the collision with the Rosses was not identified as a “scheduled vehicle” on the declarations page of National Indemnity’s insurance policy. Claiming that the unlisted Kinard vehicle was not covered by the insurance policy but by the statutory “Form F” endorsement, National Indemnity sought partial summary judgment limiting its potential liability to the statutory minimum compulsory liability limits ($100,000/300,000) rather than the $750,000 coverage of its policy with Kinard. The trial court granted partial summary judgment to the insurer on the coverage issue and the Court of Appeals affirmed. Kinard v. National Indem. Co., 225 Ga. App. 176 (2) (483 SE2d 664) (1997). We granted a writ of certiorari to determine whether a rule promulgated by the Public Service Commission (PSC), the regulator of motor common carriers in Georgia (OCGA § 46-7-2), makes an intrastate motor common carrier’s insurer liable for the amount of coverage provided by its policy or for the statutory minimum coverage when the motor common carrier’s vehicle involved is not specifically described in the insurance policy.
A motor common carrier may not operate in Georgia without obtaining from the PSC a certificate of public convenience and necessity (OCGA § 46-7-3), and a certificate is not issued unless the applicant gives and maintains bond, with adequate security “for the protection of the public against injuries proximately caused by the *267negligence of such motor carrier, its servants, or its agents.” OCGA § 46-7-12 (a). In lieu of bond, the certificate holder may file a policy of indemnity insurance which is approved by the commission and substantially conforms to all the statutory provisions relating to bonds (§ 46-7-12 (c)), or the commission may permit a motor common carrier to self-insure. OCGA § 46-7-12 (d). Whatever means the common carrier chooses to evidence its potential financial responsibility to the motoring public, the bond, insurance, or self-insured plan “is a direct and primary obligation” to any person who sustains actionable injury or loss as a result of the negligence of the common carrier or its agents. Great American Indem. Co. v. Vickers, 183 Ga. 233, 236 (188 SE 24) (1936). Stated another way, the purpose of the insurance “is not for the benefit of the insured [motor common carrier] but for the sole benefit of those who may have a cause of action for damages for the negligence of the motor common carrier,” making the insurance policy “in the nature of a substitute surety bond [which] creates liability in the insurer regardless of the insured’s breach of the conditions of the policy. [Cit.]” Progressive Cas. Ins. Co. v. Bryant, 205 Ga. App. 164, 165 (421 SE2d 329) (1992). The issue in the case at bar is the extent of the financial responsibility of the insurer of the motor common carrier which causes an actionable loss or injury by means of a vehicle not specifically described in the insurance policy.
It is undisputed at this point that National Indemnity issued to Kinard a policy of insurance with coverage of $750,000 on several specified trucks and a tractor, none of which was involved in the collision with the Rosses. Because of the strong public policy to provide protection to the motoring public, the PSC, pursuant to its statutory power to adopt rules and orders necessary to enforce the statutory scheme (OCGA § 46-7-27), promulgated Rule 1-8-1-.01 of the Rules of the Georgia Public Service Commission. It provides:
No motor carrier subject to the provisions of the Motor Carrier Act of 1931. . . shall engage in intra-state or interstate or foreign commerce, and no certificate or permit shall be issued to a motor carrier . . . unless and until there shall have been filed with and approved by the Commission a surety bond, policy of insurance (or certificate of insurance in the form prescribed herein in lieu thereof),... in not less than the amounts hereinafter prescribed, conditioned to pay, within the amount of such surety bond, policy of insurance (or certificate of insurance in the form prescribed herein in lieu thereof), . . . any final judgment recovered against such motor carrier for bodily injuries to or the death of any person resulting from the negligent operation, maintenance, or use of motor vehicles under such certificate or *268permit, or for loss or damage to property of others . . . regardless of whether such motor vehicles are specifically described in the policy or not.
The quoted portion of Rule 1-8-1-.01 requires that a motor common carrier have a surety bond or insurance policy or certificate of insurance which provides injured members of the motoring public with financial recompense for bodily injury or death and property damage caused by a motor common carrier’s vehicle, even if the motor carrier’s vehicle which caused the injury was not specifically described in the policy of insurance. That insurance coverage must be “not less than the amounts hereinafter described.” The rule goes on to set out the minimum limits of the liability of the insurer or bonding company: $100,000 for bodily injury to or the death of one person, with a $300,000 limit of bodily injuries to or death of all persons injured or killed in any one accident. It is clear that Rule 1-8-1-.01 requires the motor common carrier to provide proof of financial responsibility for injuries sustained by the public due to a vehicle owned by an insured motor carrier but not specifically described in the policy of insurance executed by the insurer and the motor carrier. The question before us now is whether Rule 1-8-1-.01 engrafts the insurance policy’s coverage to all the vehicles owned by the motor carrier, whether described or not, or whether the rule requires the issuer of an insurance policy to pay to the injured party only the statutory minimum set out in the rule for vehicles not described in the policy.
We conclude that Rule 1-8-1-.01 mandates coverage for vehicles not specifically described in the policy and sets forth the minimum coverage that must be provided, but we cannot glean from the rule the coverage National Indemnity agreed to provide Kinard should a Kinard vehicle not described in the insurance policy cause an actionable loss to a member of the public. That is, as the trial court and the Court of Appeals observed, the rule only describes the bond or insurance a motor common carrier must have to operate (one that is conditioned to pay a judgment regardless of whether the vehicle involved was described in the insurance policy), and sets out the minimum amount of coverage that must be provided by the bond or insurance coverage obtained by the motor common carrier. To discern the coverage provided in this case, we must look to the insurance policy and its endorsements executed by National Indemnity and Kinard.
The parties executed a “Form F” endorsement1 to the insurance policy. An endorsement is “[a] provision added to an insurance contract whereby the scope of its coverage is restricted or enlarged. The *269terms of such an endorsement take precedence over printed portions of the policy in conflict therewith.” Webster’s New International Dictionary (2d ed. Unabridged) (1940). The “Form F” endorsement which National Indemnity and Kinard executed and which was filed with the PSC stated that it
amend[ed] the policy to provide insurance for automobile bodily injury and property damage liability in accordance with the provisions of such law or regulations [promulgated by the PSC] to the extent of the coverage and limits of liability required thereby; provided only that the insured agrees to reimburse the company for any payment made by the company which it would not have been obligated to make under the terms of this policy except by reason of the obligation assumed in making such certification.
By executing the “Form F” endorsement, National Indemnity agreed to provide the automobile bodily injury and property damage liability coverage for losses caused by the motor common carrier’s vehicles not specifically identified in the insurance policy that PSC Rule 1-8-1-.01 required. The endorsement went on to limit National Indemnity’s liability regarding coverage for the unidentified vehicles to that which was required by the PSC regulation: $100,000 per person injured or killed, with a $300,000 maximum per incident.
We conclude that the insured and the insurer agreed that the insurer would pay the statutory minimum to a party injured by a Kinard vehicle not specifically identified in the insurance policy. The State’s public policy is achieved by the assurance to the motoring public of existence of the financial compensation the PSC has deemed minimally necessary for a motor common carrier to receive a certificate of public convenience and necessity, and the insurer has provided no more than the liability coverage it agreed to provide the motor common carrier. See Carolina Cas. Ins. Co. v. Davalos, 246 Ga. 746 (272 SE2d 702) (1980), where this Court noted that an injured member of the public cannot recover from the insurer any more than the liability fixed by the insurer’s contract of insurance and the statute. The trial court did not err in awarding partial summary judgment to National Indemnity, and the Court of Appeals was correct in affirming that judgment.
Judgment affirmed.
All the Justices concur, except Hunstein and Carley, JJ, who dissent.The endorsement was in the form approved by the PSC (Form F) for such endorsements. See Rule 1-8-1-.07 (e), Rules of the Georgia Public Service Commission.