The Trans-Canada Highway is a transcontinental federal-provincial highway system that travels through all ten provinces of Canada from the Pacific Ocean on the west to the Atlantic on the east. The main route spans 7,821 km (4,860 mi) across the country.
By using figurative language, Shakespeare creates a visual image of Octavius' army overtaking them like inescapable death. Cassius' words foreshadow later events in Act 5.