I have been on many road trips and masturbated while alone on highway. Or very minimal traffic. There are long stretches of I-80 with nothing else to do. I-25 in eastern Wyoming is good too.
Till this thread was started, I hadn’t thought about one horny night when I decided to drive around with my dick out of my pants. It felt very liberating. Windows down…nice breeze over my cock….stroking.
Cars, mine and others. On a train. Multiple times on planes. Most recently on a flight back from Spain. A couple of times on motorcycle. Although I did have to stop to finish. Both times on rural secondary roads. Once in Utah and once in Nevada.
In a car I pulled up to a self serve car wash. Was just going to throw trash out but I looked out my window and there was a woman vacuuming her car bent over in the passenger seat giving me a great view of her ass, with short shorts that said “juicy”. I started stroking and she climbed out of the car and saw what I was doing. She smiled and went back to vacuuming giving me the same view but was kind enough to pull her shorts to the side showing me her pussy. I finished and drove away.