Taxi in Madrid

Pretty much. Green light will indicate vacant. Definitely more taxis at plazas, and there are designated taxi ranks around.

That said, the center is fairly compact and strolling is part of the Madrid experience. Unless there’s limited mobility or a real time crunch, on foot would always be my recommendation.

Very easy. There will be taxis lined up near the big squares. Otherwise just wave one down.

Thank you. My wife has limited mobility.
So my next question is: any taxi in Salamanka, Toledo, Segovia, Escoreal, please?

Uber also great in both Portugal and Spain.

I haven't been to El Escorial, but there are certainly taxis in the other three, and you'd lol want one from the train or bus station to the historic center. Toledo has a quite large medieval center (in the loop of the river) that also happens to be hilly. I hoofed it so am not sure, but I imagine there are a lot of little, twisty streets a taxi cannot traverse. Perhaps someone else knows whether there are some of the little golf cart-style vehicles in Toledo; those might be helpful to you.