Stretches of the Pacific Crest Trail are also unsegregated shoulders of Highway 1.
Highway 1 runs directly on the coast. The PCT runs along the crest of the Sierra Nevada and Cascade mountain ranges-- more than 100+ miles to the east of Highway 1.
looking around the map near me for an example, there's a section of trans canada "trail" from olds to airdrie that is just highway 2A travelling in a dead straight line for about 100km.