Be honest, depending where you are traveling to & you know roughly how long the journey takes, either by GOOGLR information or the likes, do you say I can afford to go at this time because it takes !!!!!!!! time to get there or do you allow for hold ups etc?
We took 4 hours on Saturday to get from Dover to Banbury - we deliberately left early because the M25 was mostly 40mph on the gantry signs, but even so, we got there only10 mins before the time the wedding started.....
A driver that is going on a timed appointment & is running late, does not concentrate on what they are doing & often makes errors, Boxy has just explained a situation that COULD HAVE BEEN Stressful being that arrived 10 mins late.
"Will wait to see if your answer is correct Ummmm" - what do you expect me to say, I drive like a maniac leaving carnage in my wake because I'm late? Not at all, I just arrive late.
TWR, keep of the M5 Bristol area, road works ( replacing central reservation ) made me late for a funeral in Devon last Friday. Trip should have taken around 4 hours allowing for a couple of stops it took 5 and a quarter hours and the same again for the return trip.
I've seen it, I've heard it Tony, M6 Hilton Park is an example, I think you know what I mean, my answer to my transport office used to be, as long as it takes to get there, you can estimate, but that is not a positive answer.