Tourist season is beginning to get into full swing across Somerset, bringing more traffic and - yes - more caravans.

And it will soon be the busiest time of year for farmers as harvesting of crops gets under way bringing more tractors on the road.

All this means the inevitable scene on a summer's day on a Somerset road is about to get played out.

Chances are, you are going to be stuck behind a tractor or a caravan.

What is the law on slow-moving traffic though?]

Are tractor drivers obliged to move aside? Should cars pulling caravans pull to one side to let others through?

Fortunately, Wales Online has been investigating and this is what the law says about when slow tractors, cyclists, caravans and lorries should pull over.

Advice on slow moving vehicles has been given

Advice on slow moving vehicles has been given

What is the speed limit for tractors?

When you are stuck behind a tractor, you could be forgiven for imploring it to go a bit faster. The law has recently changed, increasing the speed limit from 20mph to 25mph.

There has also been a shift in the weight allowance as well, meaning that 31 tonnes can now be carried in one load. This is meant to limit the amount of journeys required and ultimately lead to fewer times tractors are on the road.

What are the speed limits for lorries, buses and caravans?

This group of vehicles are granted the permission to travel at a higher speed than tractors. Lorries and goods vehicles that weigh less than 7.5 tonnes can travel 50mph on single carriageway roads, 60mph on dual carriageways and 70mph on motorways.

If they are towing a trailer or articulated, then they are limited to 60mph on motorways. This speed limit also applies to lorries that weigh more than 7.5 tonnes.

There can be frustration when stuck behind a line of lorries

There can be frustration when stuck behind a line of lorries

Caravans and cars with trailers that weigh less than 3.05 tonnes are limited to 70mph on motorways, 60mph on dual carriageways and 50mph on single carriageways.

There is a subtle difference for buses. If they are shorter than 12 metres in length, they are limited to 50mph on single carriageways, 60mph on dual carriageways and 70mph on motorways.

If the bus is longer than 12 metres, it is still a limit of 50mph on single carriageways and they are limited to 60mph on both dual carriageways and motorways.

Can drivers let traffic past?

According to Rule 169 of the Highway Code, motorists should not hold up a long queue of traffic, especially if they are driving a large or slow-moving vehicle.

It informs drivers to frequently check their mirrors, and if necessary, pull in where it is safe and let traffic pass.

Nothing beats getting stuck behind tractors in traffic

Nothing beats getting stuck behind tractors in traffic

Does this apply to caravans too?

In Rule 169 of the Highway Code, it states that this also applies to caravans, which means that they should pull over when it is safe to avoid creating long queues of traffic.

Does this go for cyclists as well?

No, cyclists are not obliged to move to allow vehicles to overtake.

Rule 169 of the Highway Code does not mean that cyclists have to pull over for passing traffic, although police officers may suggest riding further to the left if it is safe to do so.

If the cyclists deems that the conditions are not safe for overtaking they are able to ride in the middle of the lane.

This gives them control of the flow and speed of the traffic until they feel it is safe again.

It is not illegal for cyclists to ignore cycle lanes. They are in place to improve the safety of cyclists, but it is up to their discretion if they choose to use them or not.

It is also not an offence for two cyclists to ride alongside each other, nor is it illegal for them to ride on A roads.

But they can't ride on motorways of course.

How can I overtake large vehicles?

This can be a difficult manoeuvre to do as you need to ensure that there is enough room to do this.

You should drop back, as this increases your ability to see ahead and also puts you within sight of the vehicle's mirrors.

There is a need for a calm approach when stuck in traffic

There is a need for a calm approach when stuck in traffic

Make sure you have enough room to overtake and if you doubt the safety of the move avoid doing it.

It is also important not to assume that you can follow a driver who is already overtaking the large vehicle as there may be further traffic ahead.

What is the advice from police?

There had been a number of complaints about farmyard vehicles refusing to let traffic pass, so Dyfed-Powys police issued a statement to remind drivers of tractors and over large, slow vehicles to let traffic go by when it is safe to do so.

Traffic will be on the rise this summer

Traffic will be on the rise this summer

Inspector Mark Davies said: "A few tractor drivers will travel slowly along main roads, towing long, laden trailers and not give other vehicles the opportunity to pass.

"This causes a long snake of cars behind the tractor. Driver frustration then sets in, making impatient car drivers take extreme risks trying to overtake.

"The police recommendation to slow-moving vehicles is to pull over, where it is safe to do so, and make use of lay-bys, when you have six or more vehicles behind you."

Is there any other advice given to farmers?

The National Farmers Union transport adviser Tom Price said: "The point to note is to pull in when it is safe. There could well be circumstances when it is not safe to use a lay-by, for example, if it is too small for the vehicle concerned.

"The presence of a lay-by does not automatically mean it has to be used."

So, what should you do if you're frustrated while stuck in traffic?

A spokesman for the AA urged holiday drivers to be patient while driving in the countryside, saying: "They need to bear in mind that when they drive into rural areas they are going to come up against tractors and other agricultural traffic as they are part of the landscape.

"Tractor drivers know the local roads like the back of their hands and they will pull over when it is safe to do so. If they do not pull over there is a good chance that it probably is not safe."