I do that all the time while travelling. To be able to do that thoroughly, I normally check for setup, entry positions before leaving my house to know if I will take any trade or not during that journey. I don't begin to look for setups in transit. All I do need is the right time to trigger trades. That's if I don't set pending order for them before hand. It's the same way I visit this forum or check on my SM handles while on transit. It helps me kill boredom. I can't be on a journey of more than two hours and not surf the net or peep to see what's happening with my apps. However, I try as much as I can to dodge other co-travellers from looking at my phone while I'm on it. Times are really bad. We don't know who may be lurking or looking. Prevention, they say, is better than cure.