The outrider was part of DP Ruto’s motorcade headed to Githunguri, Kiambu County, where Ruto was attending a burial.
According to reports the the officer identified as Constable Casmel Ndege lost control leading to the deadly crash.
After the accident Mr Ruto passed his heartfelt condolences to the family of Mr Ndege.
In his message the DP described the officer as a gallant, hardworking and dedicated professional.
"Deepest condolences to the family and friends of Constable Casmel Ndege who has passed on in the line of duty. He was a gallant, hardworking and dedicated professional. We celebrate him for his selfless service to this country. May his Soul Rest In Peace,” he said.