A Scary Incident

So, something scary happened to my girlfriend and her sister the other night and has me thinking.They were driving from Twin Falls to Boise Idaho on the interstate at about 3am the other night. Much of the road between the cities is only 2 lanes each way separated by a large ditch type divider and very unpopulated.They were driving a small Volkswagon Jetta Hatchback doing 80mph which is the speed limit on that highway. A large lifted truck like an F250 came up very quickly behind them and started tailgating aggressively. They changed lanes to get out of the trucks way to let it around and it followed them over. It proceeded to tailgate, swerve around, brake check and even try to force them into the center ditch for almost 5 miles. It wouldn't let them get away. They didn't get a license plate or see the occupant(s). And often there are areas of no cell service on that stretch of road.The girls finally came to an offramp (few and far between out there). They took the offramp quickly without signaling or anything and thankfully the truck either missed it or decided not to follow. If it had they would have been helpless on a deserted stretch of road that certainly has no chance to call for help.I carry an LCP everyday and on drives like that, I usually have my .30-30 or shotgun (lots of ground squirrels and coyotes to be shot out there). They were afraid for their lives and I'm sure would have been calling the police if possible.Had I been in the car and unable to call for help, I'm wondering at what point would I have been justified in drawing and firing at the truck/driver?And if you wanted to be prepared for a situation like that, what kind of gun would be ideal? It'd made me think about building an AR to keep in the car with my survival/necessities bag that always stays in the car. I know an LCP is probably the least desirable gun to have in a situation like that.Tahnks for any info or insight you can give me. via /r/CCW http://ift.tt/1MM55HW