There's loads of reasons imo lookout. A combination of a few probably, quite likely one of them being your suggestion.
I have been in a situation of driving five miles along country roads at 1am to get to someone very close to me in a dangerous situation and the police involved.
My thoughts were....... must drive slowly, I want to get there in one piece.
I mustn't get stopped by the police for speeding that will complicate everything
I mustn't have an accident as I need to get there as quickly as possible as safely as possible.
It also has the effect almost like a car accident when everything slows down and a calmness comes over you.
Adrenaline fuelled speeding doesn't come into it. imo
However this is just my experience therefore, also only a possibility imo.
Maggie,,there'd have been a thousand and one things going through his head.Firstly,,you've got to focus yourself after been wakened at an unearthly hour,,as he must have been dead beat after working 17 hours on the farm gathering in rape. Neville also would have been very tired that night too.
Then whilst driving,,you have to make sure that your mind/thoughts don't take over your driving,,as it's easy to lose concentration as you're aware. I thought it was dreadful that Jeremy wasn't given a lift.It would have been all the same if he'd had more " than a beer ",,what then.? A drink driving ban.?
I thought it was customary for the police to collect a person to take to the scene of a crime,,in case he/she was a suspect. After all,,he was the only one of the family who was not in the family home.
Did he by any chance have to drive himself back after the trauma.?
I think it was a bad move asking him to drive himself to the farmhouse,,because if the car was examined afterwards,,which it was,,how on earth would the police know if the car had been used prior to the murders.?