Is it legal for 2 motorcycles to ride abreast on a highway?

Yes, it is generally legal for two motorcycles to ride abreast on a highway, as long as they are within the lane markings and not violating any specific traffic laws. However, riders should be cautious and aware of their surroundings, as riding side by side can limit maneuverability and increase the risk of accidents. It's always best to check local laws, as regulations can vary by state or country.