But 50 years ago, police officers didn't have "blues and twos" to alert motorists, relying instead on a "stop" sign stuck on a pull-down blind.

Not many people have more knowledge of how police cars have evolved than Barry Pope, who is retiring from his job as head force mechanic after 46 years.

Grandfather-of-one Mr Pope (65) first joined the Isle of Ely Constabulary as an apprentice mechanic at the old March police station, in 1962.

The Isle of Ely force became Mid-Anglia Constabulary in 1967, when it merged with Huntingdonshire, Peterborough and Cambridge police.

It then became Cambridgeshire Constabulary in 1975.

Mr Pope, who is an avid windsurfer, said he was responsible for three Austin Westminster A99 patrols cars, five vans and 17 Velocette motorcycles – one for every village– when he first started.

He said: "Officers didn't get any luxury in those days.

"Heaters were optional extras in the cars and vans, and if an officer complained of the cold, they were told to go home and put on a thicker coat.

"The Austin Westminster A99 had a roller blind in the back window which officers could draw down, and it said 'stop' on it, in big letters."

Mr Pope and his colleagues were responsible for body repairs, re-sprays and making anything the force needed. If you couldn't buy it, you made it," he said.

He added: "Major servicing and repairs were carried out on a fixed ramp outside.

"In the winter you had to put ashes from the workshop stove on the ramp before you could get to the top."

Mr Pope, who is in charge of the workshop, has worked on many police vehicles over the years – from Triumph Tiger Cub motorcycles to the Ford Anglia with a blue door, which marked it out as a police car.

He said: "The police vehicle started with the 'single jam sandwich', which was a single reflective line in the '70s, and moved to the battenburg marking we have now in the '90s."

Blues and twos eventually replaced the single blue lights used on the roof of panda cars.

Mr Pope, who lives in March, said he was just as committed to his work now, saying: "I have only been late twice in my whole career.

"I believe our job is a crucial one, and i've been part of a great team, both in March and Peterborough.

"Officers have got to have confidence in their motor and know that it is safe."

When he retires this week, Mr Pope plans to continue teaching windsurfing at Ferry Meadows, in Peterborough.

He also aims to spend more time with his wife, Maxine, daughter Rebecca and grand-daughter.