P.R. Laws tit. 23, § 2304
If the damages are caused by collision, the following rules shall be observed to fix the civil responsibility established in § 2303 of this title:
(a) If only one of the parties incurred in a fault, it shall sustain its own damages and shall compensate the other party for all damages caused.
(b) If both parties incur in fault, the damages shall be equally divided among both, unless there is a great disparity among the faults. In this case, the damages shall be equitably distributed in proportion to the seriousness of the faults which caused the collision.
(c) Should it be impossible to determine which party was at fault, the damages shall be equally divided between both.
(d) If none of the parties were at fault, each one shall sustain its own damages.
History —June 28, 1968, No. 151, p. 459, § 3, art. 3.04, eff. 90 days after June 28, 1968.