At least four Canadian road shots in the 1948 CNJ The BIG little Railroad 26 minute promo film from1948:
A single CN single sheathed car in a nondescript moving train consist .
A single CN single sheathed car in a siding on the main line east of Westfield (Garwood/Cranford area ) with at least three other cars including a large herald SSW "Cotton Belt Route" double sheathed car.
At least 2-3 CN single sheathed boxcars and a single maple leaf herald all steel car in a moving train shot on the Newark Bay lift bridge.
A single CP 248xxx steel box in a nondescript moving train consist.
My video isn’t that good quality as to make out the actual road numbers or the car types but there are at least these four shots if not more.