My wife and I often use bike trails and there have been more than one attempted rape on a densely wooded trail we use. We also once ran into car thieves who had driven a car onto the bike trail and into the woods in order to strip it (what they were doing when we approached).
While I've never had trouble with motorists, I prefer to be armed so that I have a fighting chance against the street element. If you watch any of the true crime/forensics shows, there are many instances of couples assaulted, the male savagely mauled or killed and the female raped and sometimes slain.
Int'l Assoc. of Law Enforcement Firearms Instructors