Not to say it isn't a decent movie...

Rating: 7/10 (23 February 2019)

... just that it's so inoffensive, safe, and cliche that I feel like I've seen it a million times before. Mortensen and Ali are terrific actors, and I am thankful for them. Without their charisma (and Viggo's willingness to shove insane amounts of food down his throat), I fear Green Book would be dead on arrival.
Mostly, I think this is a movie that's desperately afraid of 'offending' anyone. For instance: if there's a scene with racist cops, there will also be a scene with a good cop down the road, just to make clear that the movie is not stating or suggesting that 'all cops are/were racist'. It's also funny that the good-cop scene happens in the snow, to let us know the characters are back in a blue state, where supposedly life wasn't so bad for a black man after all! This is one of the many simplistic moves that indicate to me that the filmmakers were willing to sacrifice the complexities of their themes for a feel-good entertainment.
The script wants both characters to 'learn' from each other and eventually change and grow, but to make this happen, it turns them into unrealistic caricatures. It's a bit frightening how Shirley is portrayed as a complete ignorant of black culture, but it had to be this way so Tony can be the one to 'introduce' him to it. Tony's transformation comes simply from witnessing racism first hand, as if he never experienced such a thing in his life before - maybe another consequence of this being a blue state-red state movie??
So besides the performances, that speak for themselves, I think it's a very uninspired effort. At one point the characters leave the car for no reason other than to have a dramatic confrontation in the rain, as if rainy night equals 'dramatic weight'. I saw it in a packed movie theater and people seemed to enjoy it. You can't blame them. The movie has a 'now everything's fine' conclusion that can leave audiences in a good state of mind - but it also
shows how simplistic it really is.