Four out of five UK airports have increased their fees for drivers dropping off or collecting people at airports this summer, according to a study.

Eighteen of the 22 airports analysed have introduced or raised drop-off fees, the RAC investigation found.

So-called kiss and fly charges - typically levied for dropping off someone as close to the terminal as possible - have increased at eight airports compared with last year.

Stansted and Luton have the most expensive initial charges at £4 for 10 minutes and 13 minutes respectively.

Manchester charges the most per minute, with drivers getting just five minutes for £3.

East Midlands, Birmingham, Doncaster-Sheffield and Newcastle all added a pound to their minimum dropping off charges.

Six airports continue to provide free drop-off facilities, including Heathrow and Gatwick.

Many airports offer short-term car parks for pick-ups so drivers can leave their vehicles and greet their passengers at the arrivals area.

Stansted hiked its prices for this type of parking the most, with a £2.50 rise to £8 for half an hour. This takes it level with Luton for the most expensive pick-up fee.

Birmingham is the third costliest at £5.50 for an hour.

RAC spokesman Simon Williams said motorists dropping off or collecting family or friends are "often left wincing" at the prices charged.

He went on: "Many travellers simply do not have easy public transport access to get to the airport and even if they do, they can't always depend on it getting them to the airport in good time.

"Many drivers dropping off their friends or family will naturally only spend a minute or two doing so, which makes the experience all the more painful.

"Doing your research on the fees charged before heading to drop off or pick up at an airport has to be the best advice."

Some airports offer cheaper rates or even no charges for using car parks further away from the terminal, which often requires a shuttle bus connection.

A spokesman for the Airport Operators Association said: "Airports that operate drop-off charges directly outside the terminal do so for a number of different reasons, including to manage congestion in capacity-restricted areas and to limit the environmental and air quality impacts of kiss and fly journeys.

"As the RAC notes, airports offer free drop-off and pick-up alternatives with good links to the terminal.

"This information ensures travellers are well-informed on the range of options to suit their needs."

- Here are the initial fees for using a car park close to airport terminals to pick up passengers, according to the RAC:

1= Luton: £8 for 30 minutes

1= Stansted: £8 for 30 minutes

3. Birmingham: £5.50 for one hour

4. Manchester: £4.50 for 30 minutes

5. Heathrow: £4.20 for 30 minutes

6. Edinburgh: £4 for 15 minutes

7= East Midlands: £4 for 30 minutes

7= Gatwick: £4 for 30 minutes

9. London City: £3.50 for 10 minutes

10. Southend: £3 for 10 minutes

11= Liverpool John Lennon: £3 for 20 minutes

11= Glasgow: £3 for 20 minutes

13. Aberdeen: £2.50 for 15 minutes

14. Newcastle: £2 for 10 minutes

15. Southampton: £2 for 15 minutes

16= Belfast International: £1 for 10 minutes

16= Cardiff: £1 for 10 minutes

18. Bristol: £1 for 20 minutes

19. Jersey: 80p for 30 minutes

20. Belfast City: Free for 10 minutes

21. Doncaster Sheffield: Free for 15 minutes

22. Leeds Bradford: Free for one hour