Good point: * Monday mornings (outbound), for most people with relatively fixed sleeping habits, going an hour earlier to the airport (say, depart home 5am inst

Good point: * Monday mornings (outbound), for most people with relatively fixed sleeping habits, going an hour earlier to the airport (say, depart home 5am instead of 6 am for 7am flight, or equivalent) is an hour's sleep lost which cannot be substituted at the airport, and reduces your effectiveness for the day. * On return legs, in principle you can substitute airport time for work time, but in my experience it's never one to one exchange. Re traffic: I agree with you in principle; but I find traffic is unpredictable for changing destinations. For repeatable fixed-circumstances situations, less so - i.e. On Monday morning, at 6am, from home to airport, on same route, traffic is actually fairly predictable over time.