I joined Hampshire police during speed patrols on Hill Lane

Every December, Hampshire police launch a crackdown on drink and drug drivers - known as Operation Holly - to catch offenders in the act and keep streets safe.

This year was no different - and to observe the work of officers on the spot, just before Christmas I joined the force's road policing unit as they carried out stops on Hill Lane - one of Southampton's speeding hotspots.

Speeding can be one of the easiest ways to catch someone under the influence so, on the night, officers were on the lookout for motorists breaching the new 20mph limit between Commercial Road and Burgess Road.

The limit is often overlooked but this time, careless drivers were met by a police officer asking them to pull over.

Officers with speed guns stood at the end of the road, using the technology to get a good indication of how fast a car was being driven.

The advantage of this system is that by the time drivers realise they're being monitored, officers have had their eyes on them for some time.

Anyone caught speeding is pulled over and breathalysed.

Chief Inspector Emma Hart said: “If somebody is under suspicion of drink driving, they'll be breathalysed at the roadside.

“And if they are under suspicion of drug driving, we'll use a drug swipe, which will detect cannabis or cocaine.

“There's also a fit test, which they will perform on the roadside as well, which will look at your reaction levels. And if you fail that fit test, you'll be arrested and taken to custody.”

While out on speed patrol, it wasn't long until officers started to notice people going a little too fast.

A motorist was stopped and issued with a ticket after driving a black Ford Focus at 40mph.

But speeding is not the only giveaway for drink or drug driving.

Officers also look out for suspicious behaviours.

If they have reason to suspect anyone may be under the influence of alcohol or drugs, they won't think twice about stopping them.

Ch Insp Hart added: “Something like cocaine or amphetamine, you'll find (drivers') reactions are faster, they may talk faster, they might not be able to concentrate, they might flip from subject to subject, and they might be more animated.

“If they're on something like cannabis, they will generally be calmer, slower in their speech to you and just maybe not quite comprehend what you're asking them.

“So, when you ask them to get out of the car, they might hesitate or not understand that.”

After an hour and a half, none of the 20 drivers pulled over tested positive for alcohol.

Five tickets were issued for either speeding or driving without insurance.

As one of the officers described it to me, “it was a successful start”.

They packed their equipment and moved to a different location.

Hampshire police officers during Operation Holly (Image: Newsquest, Jose Ramos)

During Operation Holly, Hampshire police officers team up with Thames Valley Police.

Last year the campaign resulted in 737 arrests, 286 of which were across Hampshire and the Isle of Wight.

Operation Holly runs until December 31, though officers will continue to pursue drink and drug drivers in the new year.

With New Year's celebrations just around the corner, Ch Insp Hart is appealing for members of the public to plan ahead.

She said: “If you are going to a social occasion or to visit family and you're going to drink, you need to arrange your transportation home before that event.

“You can use public transportation or a friend or walk, but do not get into your car when you're impaired.”