In most of Canada it is legal to walk on the road sides and highway sides without sidewalks, except on “schedule 1” highways which only amount to a very small fraction of the distance covered by the country’s highway system. While it is legal to walk along the highway side, it is not the preferrence of the RCMP and other law enforcement agencies since it can be a dangerous activity. As someone who has done a fair amount of highway side walking I would agree that it can be a dangerous activity, though it can also be done safely and with care.
The law requires highway walkers to walk toward traffic, not in the same direction of the vehicles as if one were hitchhiking. Hitchhiking is also legal in most of Canada, though, again, generally not encouraged by law enforcement.
Highway shoulders vary in width and grade with some being much more friendly for walking than others. Generally, the further away from a city center a highway is, the safer it will be for walkers. At the same time some more remote parts of the country have virtually no highway shoulders at all, as they traverse water ways or are surrounded by wetland and other difficult terrain.
For the most part one will find that there is ample space beside Canada’s highways for walking, but to stray very far from the road sides also makes walking exponential more difficult in most of the country. Steep embankments, heavy tree lines, swampy drainage ditches, and private property often make walking far from the road slowler and more demading, though likely safer than being near to traffic
Another option for following the highway systems in Canada is often found in the way of service roads that run parallel to the Trans Canada Highways. These roads are generally only used by local traffic and work vehicles so they are safer for pedestrians and bicycles. While often unpaved these roads offer more secure routes for pedestrians who want to follow the Trans Canada.