An at-duty police force official and a 91-year-old female include dead next a collapse on the A4 in Berkshire.
PC James Dixon dead following the bike he was galloping was in clash in a car on Bathtub Way close Rabbit Hatchway at 13:50 GMT.
The retiree, who was a occupant in the vehicle, was annihilated time the motorist, as well a female, was undertaken to clinic.
Commanders told the way would stay close for the remnant of Tue.
Thames Vale Police force told the following of kin of both of PC Dixon and the dead female include been aware.
A strength representative told commanders remained at the stage of the clash and had informed motorists to escape the region.
The occurrence has been called to the Freelance Police force Complaints Committee (IPCC).
IPCC Connect Commissar Guido Liguori told: “My thoughts and sympathies are in his families and friends and the associate of the official at the really hard period.
“IPCC investigators are visiting the stage as portion of an freelance inquiry to define the occasion that conduct to the clash.”
PC Dixon was relying at Loddon Vale police force plant, close Read.
Police force told the injuries of the motorist implicated are “no mind to be lifetime menacing”.
Tributes to PC Dixon include been located in comments on Thames Vale Police force’s Facebook web page.
Daniel Dimple told: “trip the sky and the clouds big person, it was a delight knowledge you and work in thou.”
Bernadette Ellison told: “deity beatify you Dixie, you done me laughter in yours evil feeling of humor.”