A complicated situation - I can see why you wanted some advice!

First of all, the Waze route trace. We only get supplied with part of the Waze route and it can sometime make things confusing. In this case, the report was raised after the junction. What we are actually seeing is that Waze is trying to turn the driver around and send them back to the NE for some reason. If you look between St. Luke's Rd and St Peter's Rd, you will see that the purple line has arrows pointing in both directions. That is the point where the section of Waze route we can see actually begins, heading south. Waze was telling the driver to turn right into St Peter's Rd, loop around in St Peter's Cl and then turn left back out of St Peters Rd heading back to the "roundabout". It gets very confusing when the Waze route overlays itself like this.

When I see something like that, I'd normally assume a destination problem: the driver is heading somewhere but Waze thinks they're heading somewhere else. But that's not what the reporter complained about, so let's get onto that.

First, and most importantly, the junction they are complaining about is not a roundabout. It has no "proper" roundabout signs and no signs that even suggest a roundabout. It's simply a one way system, and one that is mapped (mostly) correctly as such in Waze.

reporter wrote:As I approached the roundabout at the Datchet Road and Straight Road junction, Waze told me to take the second exit (correct)...

It's generally best not to tell reporters they got it wrong, but I'm 100% confident Waze didn't tell them to take the second exit because it's not a roundabout!

reporter wrote:...but then said And Keep Right (incorrect).

Not incorrect, but misleading. After entering the junction, they would have received a "Keep Right" at the end of this segment and they misinterpreted this as being an instruction for further round. This would not have happened if there had been a keep left/right at the end of this segment, which there really should have been. I've now altered that fork so that it gives a KL/KR correctly by adding a couple of alt-names.

I would suggest that you explain to the reporter that the junction isn't a roundabout at all; the "keep right" was intended to keep them going round the junction past Datchet Road; and that we've fixed the map so that they will then get a keep left to tell them to continue south onto Straight Rd. They haven't complained about the fact Waze then tried to route them back where they came from again, so I wouldn't mention it.

Now, I said the junction was mostly correct. It has a couple of mistakes that need correcting, which you can do.

Firstly, the geometry at the end of this segment is wrong. There's a give-way line and the presence of a yellow box junction suggests that traffic passing in front of the give-way line is sometimes heavy enough that drivers will have to pause at the give-way line and make a careful exit to head up towards Datchet Road. So I think the geometry should be altered there to give a "turn" instruction.

Secondly, although the name is technically correct, I think that this segment should have it's name removed. Currently, drivers forking right onto that segment will get "keep right onto A308 Albert Road". But they're actually heading onto Straight Road. If the name is removed, the correct name from the next segment will be carried back.

When you've removed the name, you'll then have a short unnamed segment joining a long unnamed segment. I will award maximum bonus points if you can work out how to remove the superfluous junction node.

Let me know when you're done and I'll give it a look-over.