Plenty of bad but 'the worst' in terms of consequences and the effect it had on me and the family:
Heading out of Bath on the A36 a few years ago, on 'Good Friday' of all days, for those who might know it, the Warminster Road. 30 limit up-hill. Me driving, family on board, in a queue of traffic doing 30. I see a red Corsa attempting some diabolical overtakes in my off-side mirror. Pushing his way past people in the face of oncoming traffic, I move left and let him by. He looked possessed.
Ahead of us is a Landrover with another family onboard. The road narrows and he's stuck behind it.
At the end of a straight there are a series of S bends, it goes from 30 to 40 to NSL.
We lose sight of the Corsa and Landrover as they head around the bend.
I slowed anticipating the worst and sure enough around the next bend the Landrover was across the road, the Corsa on it's side and the oncoming car smashed up (I forget what it was - probably couldn't identify it front on come to think of it).
As anyone who's come across a proper collision will testify the results are not pretty.
Corsa driver was not wearing a seat belt and got thrown out of the drivers window, taking off the back of his head. He was still conscious and combative though and screamed for a good few minutes before going quiet.
Thankfully no-one else involved was seriously (physically) injured but the woman and young female passenger (daughter?) who he collided with and the family in the Landrover who witnessed his death were understandably traumatised.
I put gloves on before trying to deal with him but ended up cutting my hand on broken glass trying to cradle his head on the floor - my blood mixed with his, my suspicions confirmed, he turned out to be an IV drug user so I had an agonising wait for Hep and HIV test results.
His parents phoned me a couple of days later, he'd had an argument with his girlfriend. They wanted to know how he had died and I lied and said "peacefully".
Ride and drive carefully out there 
