Sentence:  The most vulnerable road <WSD>users</WSD> are pedestrians, cyclists, motorcyclists and horse riders. It is particularly important to be aware of children, older and disabled people, and learner and inexperienced drivers and riders. https://www.gov.uk/guidance/the-highway-code/road-users-requiring-extra-care-204-to-225 
Meaning of the word marked with <WSD> tags:  One who uses or makes use of something, a consumer/client or an express or implied licensee (free user) or a trespasser.