Police Constable Andrew Duncan, 47, last month died in hospital two days after being hit by a car while checking vehicle speeds in Sutton, south London.
Braving wet and windy conditions, dozens of PC Duncan's colleagues yesterday formed a guard of honour at St Mary's church at East Molesey, Surrey.
His wife Claire and children Adam and Emma held back tears as they followed his coffin into the church.
London Mayor Boris Johnson, Home Secretary Theresa May and Metropolitan Police Commissioner Sir Bernard Hogan-Howe were all in attendance.
PC Duncan's boss Chief Superintendent Glyn Jones described him as a leader and spoke of his skill as a policeman. He recalled an incident where a routine traffic stop led to PC Duncan solving a string of armed robberies.
"Andrew was exceptionally good at what he did," Mr Jones said.
He said the public should honour PC Duncan for his sacrifice.