I only travel for leisure and am quite risk averse. My local airport (LHR) is about 15 miles away but takes an eternity to get to, method 1-the tube living on the southern end of the Northern line I have to travel into town and change twice with no steps, once with steps. The journey can take about 90 minutes on a good day.
If I go by car it can take anywhere from 35 minutes up to 2 hours (normally about 90 mins).
I like to arrive about 2 hours before and allow 2 hours for the journey to LHR. Strangely enough when in NYC and travelling domestically from LGA I only allow 1 hour at the airport and the exact time the MTA trip planner says I need to travel from Brooklyn, I think it may be because I trust AA to rebook me more than I do BA if I’m late (also the cost of a TATL would be considerably more).
I also prefer early flights to later ones due to the fact I need to ‘get going’ and not hang around looking at the clock