Vietnam’s speed limits for motorbikes come from Circular 31/2019/TT-BGTVT, and the structure is simple: the limit depends on the road, not on the rider’s confidence. Posted signs always override the defaults.
The default limits for motorbikes
In urban areas (khu vực đông dân cư): 60 km/h on dual carriageways and one-way roads with two or more lanes; 50 km/h on narrower roads. Outside urban areas the defaults rise for motorbikes to 70 km/h on dual carriageways or one-way multi-lane roads, and 60 km/h elsewhere. Mopeds — the licence-free 50 cc / 4 kW category — are capped at 40 km/h wherever they ride. Wherever a posted sign sets a lower figure, the sign governs.
What speeding costs
Under Decree 168/2024/NĐ-CP, motorbike speeding is banded by how far over the limit: 5 to under 10 km/h over costs 400,000–600,000 VND (Article 7(2)(b)); 10 to 20 km/h over costs 800,000–1,000,000 VND (Article 7(4)(a)); more than 20 km/h over lands in the 6,000,000–8,000,000 VND band with a four-point licence deduction (Article 7(8)(a), (13)(b)), and group speeding — riding in a pack of two or more above the limit — carries its own 8,000,000–10,000,000 VND band with a 10–12 month licence suspension (Article 7(9)(b), (12)(b)). Speeding that causes an accident lands in the 10,000,000–14,000,000 VND accident band.
The Hanoi reality
Urban arterials mostly flow below their limits; the speed violations that cost riders money happen on the ring roads and the outlying highways where 70 feels slow. Camera enforcement covers fixed locations, and the “phạt nguội” (delayed-notice) system means a tourist can receive a fine after the flight home — through the rental shop and the deposit, if nothing else.
Why the moped cap matters to renters
The licence-free electric and 50 cc category that tourists sometimes rent is capped at 40 km/h — a limit that turns a 60-zone road into a rolling obstruction if ignored, and a fine if “kept up with traffic”. The moped’s design speed and its legal ceiling are the same number for a reason.
Information, not legal advice. Verified against Circular 31/2019/TT-BGTVT via official traffic-police sources and Decree 168/2024/NĐ-CP on 2026-09-22.