Can I ask why? Having driven in both the US and europe and used GMaps in both places, I've found the lane guidance to be borderline useless. For the most part, lanes are intuitive (turning right - right lane), and when they're not, Google often gets them wrong.
And unless you've been here before and made the mistake (and got beeped at in the process) you probably won't know nor see the arrows as you're following the car in front of you.
I find it very useful (when it works)
Happened to me more than a few times, and the only way you can avoid it is if you know all the local roads, or if your navigation software knows it...
In my area, they finally started putting these in where we used to have four-way stops and the traffic flow is much better. However, people in the states are utterly baffled by them since we don't encounter them regularly. So there's usually a sign almost a half-mile back explaining what lane you need to be in depending on where you're trying to get ... and then another two signs, along with painting on the street, to tell you again as you approach.
However for pant wetting excitement in your car, I also recommend la Place du Concorde in Paris when its busy (its always busy). Its not a roundabout as such, more a loose agreement.
I am aware that European roads as a whole are rather straightforwards compared to some parts (OK most) of the world. For starters we have rules and most of the time they are nearly obeyed. However the rules are often not quite the safe as the official ones.
For example, I discovered that around Napoli, you use your entire car as an indicator. Once you wedge it into a tiny gap then people will generally give way but you have to be very quick and accurate. It may be coincidental that when me and wifey started observing properly, that we estimated that around 90-95% of cars in that area had visible damage and were generally of fairly low value (in general).
When I gave a lift to an interview candidate at my company, who happened to be Polish, he remarked upon our habit of letting waiting cars out of side streets onto the main road. "That would not happen in Poland" he said, but I'm sure it does sometimes.
Speaking very, very generally, and given my experience does not extend to Scandinavia and quite a few other local-ish lands but does include US and Canada, I would tentatively suggest that the UK is generally a safe place to drive and is, generally, a forgiving driving environment. Our road signs are possibly the best anywhere but we do have too many signs in some places.
Driving in China would scare the shit out of me and I'm pretty confident behind the wheel.
Are these common?
This is so confusing I had to view it from top down perspective and I still have no clue how you would navigate through this.
It looks like a vehicle approaching the Magic Roundabout via A4312 can use the outer ring to exit via B4289 or Fleming Way but any other exit the vehicle must spin in circles to enter the inner ring. I give up.
That about rounds it up, I would say!
The centre (which doesn't really show up on Goog maps) goes anti-clockwise, bear in mind that we drive on the left and go clockwise around a roundabout usually. You can use the outside to avoid the centre completely, which is often faster. The main problem is that it is very heavily used and hence some of the markings are scrubbed out. Also it is easy to get disorientated but even if you fly out of the wrong exit, it is easy to use a side street later to get back on track.
I have to say that I would not recommend visiting Swindon to someone who usually drives on the right hand side. To be fair I don't really recommend Swindon to anyone 8) For me, the MR is the exciting end to a two hour drive to visit a customer - just what you need to wake you up at ~0930.
Lane guidance is very helpful in these situations.
I drive it several times a year and I still need lane guidance to help.
It's also often useful to know how many lanes can be used for a turn, etc, so you can switch lanes early.
(My even-more-anecdotal experience is that Apple Maps tends to have better turn lane guidance than Google, which isn't something I'd remotely have guessed.)