Over the years the size of cars has grown yet parking spaces often remain the same dimentions of decades ago. In the UK, there is no single statutory "law" setting out a fixed size for a standard car park space, however, local planning authorities and industry guides recommend a minimum baseline of 2.4 metres wide by 4.8 metres long, though modern guidelines increasingly advise 2.5m to 2.6m wide and 5.0m long to accommodate larger modern vehicles.

But, while the majority of car parks remain at the smaller size, it can mean people are left facing difficult choices, especially when struggling to find a space in a busy car park or when there is a need to get a baby seat in and out of the vehicle. This leaves some people parking close to the edge of the line to allow more space on the other side - or even straddlng two bays.

However, a quick look on social media shows people are finding themselves on the wrong side of the car park rules along with hefty penalties. And this can be just for touching a line that is marking the bay.

One poster took to Facebook to say she had been landed with a penalty charge notice after visiting a cinema in Hartlepool. Admitting she had "not parked great as it was a bit of dump and go because of the film was starting" she warned people that she had been given a "100 fine" for parking on the line.

Posting a picture showing her front driver's side tyre was touching halfway across the bay marking, but not crossing it completely, she said: Parked here a few weeks ago, and got a 100 fine for this! Apparently Im not parked wholly within the bay and I must be parked within the confines of the white line'.

"Now I argued what boundary meant and said that as long as my car was not over the outer line, I felt it was in the boundary. But no.

"So be warned. If your car touches the white line in any way, it's an automatic fine. Even if the car park is completely empty and youre not obstructing anyone."

In a response to her appeal, Viking Solutions, which sent the charge, said: "The photographs taken of the vehicle by the Viking Solutions warden clearly show that it was not parked in a single marked parking bay".

It added: "If a vehicle is parked on the bay marking lines, it is not within the bay."

So what are the rules?

Most car parks have their own rules - but the majority say you must be parked "wholly within the bay". This means even touching a line can incur the penalty charged for that particular car park, as was the case at the Hartlepool cinema.

To see what the rules are in individual car parks you should read the terms and conditions which should be displayed there. If the rules say the vehicles must be parked wholly within a bay, or other similar wording, then it is likely you could be given a fixed penalty notice.

Council-run car parks also usually have the same regulations. Gateshead Council for example has set out the rules for its car parks warning: "You must park completely inside the bay markings. If someone else has parked incorrectly, not leaving enough room for you to use the space beside them, you should not use the space unless all of your vehicle can fit inside the bay markings.

"You cannot use any area that is not marked as a parking bay. Any vehicle parked with at least one wheel outside the bay markings may receive a Penalty Charge Notice." It says a charge of 50 is issued for breaching this, halved if paid within a discounted period.

Luton Council also warns people using its car parks they can be charged 50, reduced to 25 if paid in 14 days of issue, if they fail to park "correctly within the markings of a bay space".