Depends on the trip.
If it's normal project work, which we can get done a day later or at another time if we don't meet as scheduled - if I'm delayed, I'm delayed, and we'll deal with it.
If the world will end if I'm not in their president's outer office by 9 am Tuesday, I'll make sure that Plan B, Plan C and perhaps Plan D will all get me there in time.
There is no general rule.