Robert Wayne Palmer has entered guilty pleas to causing the deaths of two charity cyclists on the A30 last July by dangerous driving.
Palmer also pleaded guilty to a charge of dangerous driving resulting in serious injuries to another driver on September 21 in a road traffic collision on the A30 near Whiddon Down, Okehampton, Devon, while he was on bail for the fatal collisions.
On both occasions he was driving a heavy goods vehicle.
Toby Wallace and Andrew McMenigall were killed in a road traffic collision on July 2, 2013 while they were cycling along the A30 Road near Summercourt, Newquay, Cornwall to raise funds for the Kirsten Scott Memorial Trust.
Palmer was released on conditional bail, together with an interim driving disqualification, until Monday, September 1 in order for reports to be prepared.
Toby Wallace was born in England. He went to school in Southampton and studied at Cambridge University before working in London, Sydney and Philadelphia. He died aged 36.
At the time of his death he and his wife Claire lived in Philadelphia, in the United States.
Andrew McMenigall and his wife Anne lived in Edinburgh with their two children, Jennifer (15) and Lucy (12). He died aged 47.
Both Andrew and Toby were heavily involved with many charities and were also coaches and athletes in their individual sports.
Many awards, events and substantial charity funds have been raised in their names, including the building of two primary schools, The Toby Wallace School and The Andrew McMenigall School.