This map is an excellent companion to the author's Canada by Train: The Complete VIA Rail Travel Guide. While the book provides the detailed information, this map gives a good sense of the overall distances between towns, and how developed or isolated the various sections of the route are. I found it very useful for preparing for my trip on the Canadian, and many people on the train wanted to borrow it for a while.
I found that I didn't use it much on the train, because the book provided much more information with exact mileposts, but I was very happy to have it. It was interesting to compare the route of the VIA Canadian train with the Rocky Mountaineer that takes the original, more southern route of the Canadian Pacific.
I am only giving this map four stars because I wish the author had expanded the scale and provided more detail than on the similar map of the entire country. But if you are taking the Rocky Mountaineer or just the western section of the Canadian, this map is fine. The author did a great job and the map is extremely well constructed, sturdy, usable but not too bulky.