The Berishas appeal a Windham Superior Court denial of their motion for partial summary judgment, filed subsequent to a jury trial and verdict in their favor in a negligence action brought against them by the defendant, Robert Hardy.
In January, 1978, the Berishas and Hardy were involved in an automobile accident in Mount Holly, Vermont. In September, 1980, Hardy filed a complaint against the Berishas claiming the accident was caused by their negligence and praying for damages for personal injury, lost wages and loss of future earning power. In November of the same year, the Berishas filed a complaint against Hardy asserting that his negligence was the sole cause of the accident and requesting money damages for personal injury and loss of consortium. Hardy’s suit was tried first, and in May, 1982, the jury found him to be 52% negligent and the Berishas 48% negligent. See 12 V.S.A. § 1086. Hardy appealed the jury’s verdict to this Court in June, 1982. In September, 1982, the Berishas filed a motion for partial summary judgment, claiming that Hardy would be estopped from denying liability in a trial on their November, *1381980, complaint. In denying the Berishas’ motion, the court stated that their motion appeared to be meritorious, but that the decision which this Court would render on Hardy’s June, 1982, appeal could nullify its ruling on the motion. The Berishas sought and were granted leave to appeal to this Court. V.R.A.P. 5.
Under the doctrine of res judicata, a judgment bars a subsequent trial only if the parties, subject matter and causes of action are identical or substantially identical. Hill v. Grandey, 132 Vt. 460, 463, 321 A.2d 28, 30 (1974). The doctrine of collateral estoppel, which is a more limited concept than res judicata, estops a party from relitigating “those issues necessarily and essentially determined” in a prior action. Land Investment, Inc. v. Battleground Associates, 138 Vt. 316, 326, 415 A.2d 753, 759 (1980). Both doctrines have as their final goals the elimination of repetitive litigation, Alpstetten Association v. Kelly, 137 Vt. 508, 513, 408 A.2d 644, 647 (1979), and “repose to litigants.” Town of Springfield v. Vermont, 521 F. Supp. 243, 246 (D. Vt. 1981).
In the instant case, the Berishas’ and Hardy’s causes of action arose from the same occurrence; each sought damages for the asserted tortious negligence of the other. After hearing the testimony in Hardy’s suit against the Berishas, the jury found that the Berishas and Hardy were both negligent, that the negligence of each was a proximate cause of the accident, but that the Berishas were less negligent than Hardy. Since the jury rendered a judgment on this issue of liability as between the Berishas and Hardy, the judgment is conclusive as to this issue in a second suit between these parties based on the same tortious act. In re Estate of Leno, 139 Vt. 554, 557, 433 A.2d 260, 262 (1981).
Hardy claims that, because his insurance company will be defending him in the Berishas’ negligence suit against him, V.R.C.P. 13(a) (3) renders the doctrine of collateral estoppel inapplicable. Under V.R.C.P. 13, a responsive pleading must state any counterclaim that arises out of the transaction that is the subject matter of the opposing party’s claim. Exempted from this rule of compulsory counterclaims are claims for damages covered by a liability insurance policy *139under which the insurer has the right or obligation to conduct the defense. V.R.C.P. 13 (a) (3). Hardy argues that application of the doctrine of collateral estoppel would nullify the provisions of V.R.C.P. 13(a) (3). However, Rule 13(a) (3) does not absolutely protect a defendant’s affirmative claims from the applicability of collateral estoppel. Since Hardy was not compelled under our rules of procedure to assert any affirmative claims in response to the Berishas’ November, 1980, complaint, he should have asserted his claim as a permissive counterclaim. V.R.C.P. 13 (b).
This is so, not because of the rule, but because facts crucial to the affirmative claim that have been determined adversely to defendant in the prior suit may not be relitigated by virtue of that branch of res judicata called collateral estoppel, or estoppel by verdict.
Reporter’s Notes, V.R.C.P. 13. In Hardy’s suit against the Berishas, the jury found that his negligence outweighed the Berishas’. The question of liability for the January, 1978, automobile collision has been established, and Hardy cannot re-litigate that issue in a subsequent trial between him and the Berishas. Trapeni v. Walker, 120 Vt. 510, 144 A.2d 831 (1958).
The Berishas’ motion for partial summary judgment must be granted. Cody v. Estate of Cody, 134 Vt. 113, 115, 352 A.2d 684, 685 (1976). As previously noted, at the time the trial court denied their motion, Hardy’s suit against them was on appeal to this Court. Under V.R.C.P. 62 (e), that appeal stayed final judgment, and the Berishas’ appeal of the denial of their motion for summary judgment was not properly before us. V.R.A.P. 4. Plowever, since Hardy’s appeal has been heard by this Court and the judgment affirmed, Hardy v. Berisha, 144 Vt. 130, 474 A.2d 93 (1984), to avoid further litigation we will treat the Berishas’ motion as having been made subsequent to final judgment.
Reversed and remanded for proceedings consistent with the views expressed herein.