Roy Woods had been talking on a hands-free phone when he hit Alan Couper outside a golf club last year.
Cox Green Death: Parents' Appeal
The father of a man who was found dead on a slip road in Maidenhead said he cries himself to sleep every night because he does not know what happened to his son.
Marc Williams, 22, was discovered on the south-bound entry slip of the A404M at Cox Green in the early hours of December 1 last year.
Today his parents Mark Williams and Joanne Parker made an emotional appeal for help in solving the mystery surrounding their son's death.
Police believe he was hit by a car or another vehicle that failed to stop at the scene. Mr Williams said: "You cry yourself to sleep every night, because we don't know what happened, we need to know what happened.''
Appealing directly to whoever may have been involved in the crash, he said: "If you are that person would you please come forward. You are carrying a terrible burden and a terrible thing has happened, but we are carrying a terrible burden too.
"We just need closure and some understanding as to how and why Marc died.'' Ms Parker said: "We just need them to come forward. Don't be frightened, it doesn't matter who you are, it doesn't matter what you know, just come and help.''
Men are less likely to talk than women with 54% of women having had a conversation compared to 37% of men.
Theresa May has now signed a letter to trigger Article 50, the start of the official process to leave the EU.
MTR will run the franchise with First Group for seven years from August, taking over from Stagecoach.
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