I can't do a like for like comparison as I don't have a pilots license

As a passenger I'd prefer to be flying than being a passenger in someone else's car. Being in control is one of the nice aspects to driving which is lost when you're a passenger.

As a driver I'd say anything up to three hours driving is fine, longer if the alternatives are poor (e.g. No direct flight or the train service is rubbish - such as Manchester - Newcastle, Edinburgh - Leeds, etc the train is slower than driving and facilities are poor).

Stuck for multiple hours on the M62 earlier this year due to an accident ahead caused by heavy snow. I was actually very relaxed and calm about the whole thing. I was very happy that I could sit in comfort, control my own music and temperature. There was nothing I could do about the situation so no need to get worked up.