We don't have synonyms for motorways yet — it may be a rare, specialized, newly coined, or misspelled word. The closest thesaurus entries we have are motorway, doorways and motorcars.
(n) :
(UK, Ireland, New Zealand, Queensland, New South Wales) A highway with grade-separated crossings (rather than level crossings) and designed (and only permitted) for high-speed motor-traffic (in Europe motor vehicles with a higher speed limit than 40 km/h) running in two directions on one separate carriageway each.
(n) :
(chiefly US) A racetrack venue designated especially for the sport of auto racing.
(n) :
(UK, Ireland, New Zealand, Queensland, New South Wales) A highway with grade-separated crossings (rather than level crossings) and designed (and only permitted) for high-speed motor-traffic (in Europe motor vehicles with a higher speed limit than 40 km/h) running in two directions on one separate carriageway each.
(n) :
(chiefly US) A racetrack venue designated especially for the sport of auto racing.