There have been, what can only be called, "glitches" in the statistics relating to road traffic accidents here in the UK and in Europe for some time now. There seems to be a tenuous connection to weather conditions but not in the way most people would expect. These mainly occur when the conditions are bright and dry and most frequently at roundabouts (insert American term here!), especially where the "priority" and first joining junctions are at 90° or sharper angles to each other. What seems to happen is that two vehicles " T-bone" with the vehicle entering from the priority junction invariably being the size of your average family and rarely anything larger than an MPV.
I think I've come up with a possible reason why it happens. It may very well be the placement of the indicators on the front of the vehicle. Some manufacturers currently have models where they are well back down the side of the vehicle.
Let's face it, I am paranoid so I immediately assume the other driver is not concentrating as they approach. So if I don't see a near-side indicator, I brake and give way. OK, this behavior normally leads to me pissing off those behind me as the other car has then turned into the road I've been joining from, but the number of times a car has joined and I have seen the rear indicators actually on is at least equal to those where they aren't.
There can only be two conclusions: one, the front lamp is broken: two, the design of the lighting cluster means that the indicator isn't visible unless the angle between the two vehicles is less than a certain amount.
Number one does happen, but you can tell this from the rate of the flash: practically all the electronics to operate them are designed to run at a far faster rate if a lamp blows or falls out(!).
Conclusions. There is no substitute for concentrating on what you are doing, especially if you are behind the wheel. But the automotive designers need to examine where the line between style and safely comes and do a little re-designing.