The Check In feature in the new version of iOS will save lives and deter assaults. If you haven't checked it out, it's got a little complexity, but the basic idea is that you pick a sort of "safety partner." Using Check In (inside Messages: tap +, then tap Check In), you pick someone and then set a timer or choose a destination (including travel time and a margin). For a timer, your iPhone asks you to respond at the end of the time. If you don't in 15 minutes, it alerts your Check In buddy.