Flatbed vs Lowbed Trailer: Key Differences and When to Use Each for Oversized Cargo
In cargo transport, choosing between a flatbed trailer and a lowbed trailer is not just about picking a suitable vehicle—it directly affects safety, operating efficiency and transport cost. From hands-on experience transporting many types of oversized and heavy-lift cargo and project equipment, the H-Cargo team has found that the key differences between these two trailer types lie in deck height, load capacity and how the cargo's center of gravity is controlled throughout the journey.
In this article, H-Cargo's heavy haulage specialists analyze the features of each trailer type in detail and compare their advantages, limitations and real-world applications to help businesses choose the most suitable transport solution for each type of cargo in Vietnam.
Table of contents:
I. What Is a Flatbed Trailer and When Should You Use It?
A flatbed trailer is the most common trailer type in road transport, with a flat deck, no side walls and no roof.
1. Common flatbed trailer dimensions
Deck height: about 1.5 m from the ground.
Width: about 2.5 m.
Length: commonly 12 m, also 13 m, 14 m, 17 m and 18 m; extendable flatbed trailers can be extended further, up to about 23 m depending on the type.
2. When should you use a flatbed trailer?
Flatbed trailers suit cargo that is long but not tall:
Steel pipes, steel coils, steel plates.
Bridge girders, precast concrete components.
20-foot and 40-foot containers (trailers with container twist locks).
Packages up to about 2.7 m high, so the total height of vehicle and cargo does not exceed 4.2 m.
II. What Is a Lowbed Trailer and When Should You Use It?
A lowbed trailer (also called a low loader) has a deck that drops deep into a U shape, or a flat deck very close to the ground, lowering the overall height and center of gravity of the cargo.
1. Common lowbed trailer dimensions
Deck height: about 0.4 - 0.9 m, around 0.6 - 1.1 m lower than a flatbed trailer.
Width: about 3 - 3.6 m, wider than a flatbed for greater stability. Note: an overall width above 2.5 m is classed as oversize in Vietnam and requires a road permit.
Length: commonly 12 - 14 m; extendable models can be longer.
2. When should you use a lowbed trailer?
Tall cargo: industrial tanks, silos, boilers, transformers. The low deck reduces total height to pass under overpasses, toll stations and power lines.
Heavy cargo needing a lower center of gravity: excavators, bulldozers, crawler cranes, construction equipment. The low, wide deck keeps the cargo stable and reduces the risk of tipping when cornering.
Related articles:
- Types of Trailers for OOG Cargo Transport: How to Choose by Payload and Number of AxlesIII. Flatbed vs Lowbed Trailer Comparison
Criteria | Flatbed trailer | Lowbed trailer |
Deck height | About 1.5 m | About 0.4 - 0.9 m |
Deck width | About 2.5 m | About 3 - 3.6 m |
Length | 12 - 18 m (extendable up to about 23 m) | Commonly 12 - 14 m (extendable models longer) |
Cargo center of gravity | Higher, requires care with tall, heavy cargo | Low, more stable |
Suitable cargo | Long, low cargo: steel pipes, bridge girders, containers | Tall, heavy cargo: tanks, boilers, construction machinery |
Rental cost | Usually lower | Usually higher as a specialized vehicle |
IV. How to Choose a Trailer Based on a Route Survey
Cargo dimensions are only the starting point. H-Cargo confirms the trailer type after a route survey:
Total height of vehicle and cargo: under Circular 12/2025/TT-BXD, vehicles over 4.2 m high from the road surface (container trucks over 4.35 m) are classed as oversize and require a road permit. If cargo on a flatbed exceeds this limit but stays under 4.2 m on a lowbed, the lowbed is usually the simpler option.
Actual clearance on the route: overpasses, toll stations and power lines may be lower than the general limit, so actual measurements must be taken on each route.
Lashing plan: the wide deck of a lowbed trailer provides better lashing angles, securing tall, heavy cargo more firmly.
Need help choosing a trailer for a specific package? Send the package dimensions and weight for H-Cargo's advice.
V. Heavy Haulage Projects Completed by H-Cargo
Oversized boilers: transported 2 boilers 4.3 m high from Cat Lai Port to Ben Cat, Binh Duong, a typical tall cargo requiring reduced overall height.
Heavy machinery and equipment: transported 4 flat rack containers of heavy machinery to Long An.
150-tonne crawler crane: transported a crawler crane shipment from Vung Tau to Cat Lai, with the equipment dismantled and packed in 40'HC, 20'DC, flat rack and open top containers.
VI. Frequently Asked Questions
How long can cargo on a lowbed trailer be? Common models are about 12 - 14 m long; some extendable lowbed trailers can be longer to carry cargo that is both tall and long.
Is renting a lowbed trailer more expensive than a flatbed? Usually yes. A lowbed is a specialized vehicle with higher investment cost and often requires a road permit, so rental rates are usually higher than for a flatbed.
Which trailer should be used for 3.5 m high cargo? A lowbed trailer. On a flatbed about 1.5 m high, the total height is about 5 m, exceeding the 4.2 m limit. On a lowbed with a deck of about 0.4 - 0.7 m, the total height can stay under 4.2 m; if it still exceeds the limit, a road permit and route clearance survey are required.
Does a lowbed trailer need a road permit? A road permit is required when the vehicle and cargo exceed dimension limits (width over 2.5 m, height over 4.2 m, length over 20 m) or the gross weight exceeds 48 tonnes.
VII. Conclusion
Flatbed trailers suit long, low cargo and are usually more cost-effective; lowbed trailers suit tall, heavy cargo that needs a lower center of gravity. The final decision should be based on dimensions, weight, permitted height and actual clearance on the route.
Before hiring a truck, businesses should do 3 things:
Measure the exact dimensions and weight of the package.
Calculate the total height of vehicle and cargo for each trailer type and compare with the 4.2 m limit.
Survey the route to know overpass and power line clearances and whether a road permit is needed.
H-Cargo advises on trailer selection, route surveys and permits for oversized and heavy-lift cargo in Vietnam. Send your package details to receive a suitable transport plan.
Author: Navy Ngo - Project team
Contact us for a free consultation:
H-Cargo International Logistics
· 113-115 Ung Van Khiem St., Ward Thanh My Tay, Ho Chi Minh City
· Tel: +84 888 909 186
· Email: project@hcargovn.com
· Web: www.hcargovn.com
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