Having spent a week traveling through Portugal by car (including popular tourist places, such as Obidos, Alcobaca, Batalha, Tomar, Evora, Sintra; but also less-traveled or difficult to reach areas, such as Castelo Almourol and Marvao), this map was a wonderful and trusted companion!
Descriptions of roads, villages, towns and distances were universally reliable and precise. The level of detail is wonderful, including (third-grade) roads to somewhat isolated places, such as the Almourol Castle.
We paired this map with pre-printed directions from Google Maps (which also proved very accurate) and in three days and over 900km of travel (on major highways and minor local roads, including one-lane barely paved ones) lost our way only a couple of times (for which we can't really blame Michelin's excellent map).
This map is a highly recommended tool for those who plan to travel in Portugal by car!
A side note to those car travelers - we found the Portuguese roads to be of excellent quality -- particularly true of the major highways (which are mostly toll roads and are relatively expensive by US standards, but the road quality, the well-organized rest areas and frequent gas stations, make the expense worthwhile).