I have only just watched the last two episodes and have to say that it was far better than early posts on this thread suggested! (IMO)
I liked the way it was filmed in a straight forward way no flashy clever, clever, twists and tweaks.
When I first started I thought it must be a remake of an Australian crime series also based on real events, and when realising it wasn't but was about young women innocently trusting someone to give them a lift home after missing the bus, felt really sad.
So would recommend this. Not up there with Blue Lights or Happy Valley but a lot better than some of the slush in the 9pm slot.
As a side issue, wasn't sure about the clothes as being that authentic for the period but then sometimes I thought spot on.
As were the unpleasant bigoted attitudes.
I spent the whole series thinking where have I seen the lead actor before, and after it was over found out it was Downton Abbey.
I'm not going to give away the actual ending but do wonder if that could have happened.