Pavement crack segmentation is a critical task for improving road safety, supporting pavement management systems, and prioritizing maintenance actions in limited-data conditions. This study conducts a comprehensive evaluation of six YOLO-based instance segmentation models, comprising YOLO26 and YOLO11 variants (n, s, m), for pixel-level pavement crack segmentation using the CRACK500 dataset. The dataset, containing 500 pavement crack images with one crack class, was prepared in YOLO segmentation format and split into 350 training images, 75 validation images, and 75 independent test images. All models were trained under a unified experimental configuration. Performance was assessed using Mask mAP@50-95, Mask mAP@50, Precision, Recall, and F1-score. Results showed that YOLO26m-seg achieved the highest validation Mask mAP@50-95 of 0.2972 and was selected for testing. On the test set, it obtained a Mask mAP@50 of 0.5003 and a Mask mAP@50-95 of 0.1809. Increasing the input size to 640 × 640 improved Mask mAP@50-95 to 0.2554. Statistical validation using the Friedman test confirmed significant overall differences among models (χ² = 11.578, p = 0.0411), although Kendall’s W = 0.0322 indicated a small effect size. Finally, predicted masks were converted into Crack Area Ratio values to classify crack extent into low, moderate, and high severity levels. The innovation lies in providing a statistically supported YOLO benchmark and linking segmentation outputs to automated severity screening.