The motorist killed in the fatal collision on the A413 in Amersham on Friday (May 26) has been formally identified as an off-duty police officer.
Emergency services were called to the collision, which happened between the A255 Gore Hill and the A413 London Road East.
Mr Caddy died of his injuries at the scene.
Tributes have been made to the “dearly-loved” officer.
A statement, released on behalf of his relatives, said: “The family of Simon James Caddy is sad to announce his death as a result of a collision between his motorbike and a car.
“He had a unique ability to spread joy and humour to all he came into contact with.
"So dearly loved by family and friends, he will be deeply missed and forever with us in our thoughts.
“We would like to help support the police in encouraging anyone who may have any information, however small, to please come forward and contact the police to aid their enquiries.”
Mr Caddy joined Thames Valley Police in 2007, beginning his career as a Police Community Support Officer in Amersham.
He took on the role of PSCO in Little Missenden and as a student police officer before finally becoming a Road Policing officer in Amersham in 2015.
Superintendent Simon Dodds, head of roads policing in Thames Valley and Hampshire, paid tribute to Mr Caddy.
“We have tragically lost a member of the police family who worked tirelessly for the communities he served,” he said.
“Our thoughts are with his family and friends at this incredibly difficult time and they are being supported by a specially-trained family liaison officer.
“We are also offering welfare support to PC Caddy’s colleagues, many of whom counted themselves among his friends.
"Those who were close to Simon are deeply upset but are continuing to display professionalism despite these tragic circumstances.”
Anyone who witnessed the collision or who has information which could assist the investigation should contact the 24-hour Thames Valley Police enquiry centre on 101 quoting URN 1619 26/5.
A 33-year-old woman from Aylesbury was arrested on Saturday (May 27) on suspicion of causing death by dangerous driving and on suspicion of driving while unfit through drink or drugs in connection with the collision.
She has since been released under investigation.