Despite its age, this book is extremely readable and relatable. Adam and Roger are both instantly lovable characters with memorable personalities. It is easy to empathize with Adam's frustrations at losing his father and it is fascinating to see how he gets by on his own. Adam's travels on the road show the reader many informative glimpses into how different types of people lived during this time - a ferryman, a priest, thieves, etc. - and the story becomes much more than just a boy's search for his lost pet. The ending is also very well done, and things wrap up nicely, but believably.
Compared with Catherine, Called Birdy, Adam of the Road is a much more true-to-life example of medieval historical fiction. The author doesn't try to impose any particular agenda onto the story in order to engage or pander to contemporary readers. Rather, she just tells a compelling story and allows historical truths to speak for themselves. This book is also notable among many of the others historical fiction novels I have read because the subject matter is so mundane. Adam is not escaping an unwanted marriage, saving a potter's career, rescuing a man about to be maimed by a tiger, running from Pompeii as it collapses around him, or saving his mother from poverty. He's just looking for his dog, and his dad. And because the author is such a great storyteller, that is enough.