You will be strongly (and rightly I think) advised NOT to drive upon arrival. Yes, I think you will find it a bit difficult to drive there--not so much the actual physics of it, which you could get used to very quickly, but the traffic, the unfamiliarity, the wanting to look; my husband last August did GREAT but it was after 4 nights in London and he still had some very tense moments. We don't see your itinerary here, but I'd strongly urge you to stay around London/LHR/Windsor upon arrival (maybe for a few days?) and get the car the next morning at LHR and head out. Some may say it strongly, some more acidly, some mildly, but the urging will be the same--don't drive upon arrival. Too many factors to make you distracted. Rest and start fresh one morning. I do hope you are spending time in London--if so, for us it worked well to spend the arrival end of our 2 week trip in England staying by in London, then renting a car, then going on our 9 day driving tour, returning the car back at LHR before our flight.

It isn't that difficult to drive in the UK. However, if you are going to be getting off a long flight such as from the US, I would recommend that you take it very easy driving the first day. You will probably be very tired and jet lagged which does not make for an enjoyable driving day and may be very dangerous for you.
I did this once about ten years ago and swore I would never again get off a flight and into a car. I always wait until my body has caught up. There are a lot of little differences that can throw you off if you are not 100% alert.

I agree 100% with texasbookworm.

Driving more than a very short distance after an overnight sleepless fight is not recomended. Nor is driving on the wrong side of the road immediately after such a flight.

I would change your dates to arrive earlier so that you have some time to recover from the flight before you get behind the wheel. Also, unless you always drive a stick shift I would rent an automatic - so if there is any sort of emergency - or if you become confused (esp by a roundabout - which we have very few of in the US) you don't inadvertently do the wrong thing.

Oh - and driving in the UK is generally not a problem- as long as you're wide awake - and practice on a couple of roundabouts. And have a good navigator.

You don't mention what kind of driving you usually do and how experienced and confident a driver you are. That makes a difference. You most likely will be renting a manual shift. Be prepared fro roads much narrower, and with no verges to stop and get your bearings. LOTS of roundabouts and walls and hedges very close to the car (and the front seat passenger).

As an Australian used to driving on the left, I found driving in the UK much more challenging than I found driving on the "other" side in the US, where driving conditions were much more what I'm used to. But I always think, other people do it so why not me?

I agree with not driving on arrival. Of course a trip from Australia is even longer but I was very glad to make a base in Windsor for a couple of days to recover from the plane and the stress of picking up the car and the short drive. There's plenty to see in Windsor and you can head out and enjoy seeing Stonehenge and environs at your leisure next day.

I stayed here http://www.bbandbwindsor.com/ an easy stroll along the riverside into Windsor town.

You might be interested to read my trip report

http://www.fodors.com/community/europe/eigasukis-english-experience-april-2009-somewhat-belated.cfm

Enjoy your trip. I'd love to have spent more time in Glastonbury bu the weather was not kind for me.

On 3 different trips to the UK I have driven with absolutely no difficulty. It takes a very short while to adjust and you do need to keep your wits about you. In April we are flying into London from Canada and will pick up a rental car at heathrow. We have decided to go the short distance to Windsor to stay the first night. It's probably not a good idea to travel too far after arriving. For accommodation have a look at trip advisor.

One thing that makes it much easier is rent an automatic. It costs a bit more but it's a heck of a lot easier.

Hardest part of shifting over each time I drive in the U.K. is not driving on the "wrong" side of the road, but the fact that the shift lever is on the left. In the States, my spinal column takes over, and the shifting is automatic. In the U.K. I have to consciously think each time I want to change gears, even though the gear pattern is the same. I think, "Drop down a gear", and my left hand says, "Huh?".

If you are at all nervous about this part of driving, try to get an automatic, even though they are sometimes difficult to find and really expensive.

"Is it difficult to operate a car in the UK after driving all my life in the US?"

I'm not suggesting that you read the entire Highway Code from cover to cover before you drive over here but maybe a few searches on the internet will acquaint you with the differences of driving here as opposed to the US.
Roundabouts: http://en.wikipedia.org/wiki/File:UK_Roundabout_8_Cars.gif
BTW they're not always that big or that busy.

Speed Limits: http://www.abd.org.uk/know_your_speed_limits.htm
One of the main problems for American drivers seems to be that they are never sure of the speed limits on the main roads (national speed limit sign, white circle with black diagonal stripe), this website should get you started.

"One of the main problems for American drivers seems to be that they are never sure of the speed limits on the main roads"

It's simple really - if you are constantly overtaking then you are are going too fast, if cars are constantly overtaking you then you are going too slow.

You have two main problems: • Driving the day of arrival; and • driving in/near Glastonbury on May 1.

That is a Bank Holiday weekend and even if there wasn't a mob scene at Glastonbury for Beltane, the roads will be crowded. parking will be difficult for sure.

the driving itself isn't a problem -- after a couple of days to recover from the flight/jetlag. The first day however, it could be deadly.

Do you mean this year or 2012? If this year, have you booked flights yet? If not, I'd move the trip forward and stay in London car-less for at least a couple of days.

Also -because of the crowds in and around Glastonbury that weekend, I'd book a B&B (preferably for 2 nights) ASAP in Glastonbury or a nearby village or in Wells - one that has parking. And walk or use buses to get around.

hi Biglou,

definitely what galiano said. we made the mistake of picking up a car straight after we arrived in Toronto after a transatlantic flight and it was horrendous but after a night's sleep everything was so different and much easier.

a night in windsor is hardly a penance, and then you'll be able to start your driving safely the next morning.

It's not difficult to get an automatic car - as long as you pick it up at a major location - like an airport. Also, automatic is somewhat more - not a lot more unless you move up several car sizes (the smallest cars don't come in automatic - as long as you're getting a larger size car anyway automatic isn't really that much more if you shop around).

And be aware that the smallest size cars are smaller than offered by most rental agencies in the US.

As others have said, get a good sleep before tackling: 1. a new unfamiliar car. 2. steering wheel and gears wrong side, 3.manual gearbox and 4. driving on the 'wrong' side of the road. It's an accident waiting to happen.

I manage to drive on continental Europe (the 'wrong side') with both my car and a hire car, its a bit tricky at first but you very quickly get the knack.

Keep a close eye on speed limit signs and look out for cameras.

As Janis has explained, May day and the week before will be very very busy. So think ahead.

Good luck and have a great time !!

Muck