Here's why:
* Their relationship is complex and familial: Road and Allen have a unique bond built on shared experiences, mutual respect, and a sense of family. Road sees Allen as a younger brother figure, and Allen cares deeply for her despite her sometimes chaotic nature.
* Road's nature: Road is an artificial soul and doesn't experience emotions the same way humans do. While she can mimic human feelings, her primary objective is to serve the Millennium Earl, and love isn't a part of that.
* No romantic interactions: Throughout the series, there are no instances where Road displays romantic interest in Allen or vice versa.
Therefore, it's safe to say that Road Kamelot is not in love with Allen Walker. Their relationship is platonic and built on a foundation of respect, care, and a sense of belonging.