The technical requirements for vehicles are largely derived from EU legislation, but national regulations regarding road use, registration, roadworthiness testing and taxation also play an important role.
The width, height and length of vehicles
The maximum allowed height of a vehicle is 4,40 meters. This cannot be exceeded while the the vehicle is unloaded or with the axle lifter in upper position.
The maximum allowed width of a vehicle is 2,60 meters. (For a sedan or a bus it is 2,55 meters).
The maximum allowed length of a vehicle is 13 meters (other than a bus).
Trucks and trailers
| Truck | Maximun allowed weight |
|---|---|
 2-axle truck | 18 tonnes |
 3-axle truck | 25/26/28 tonnes |
 4-axle truck | 31/35 tonnes |
 5-axle truck | 42 tonnes |
| Trailer type | Measurements |
|---|---|
 Semi-trailer | Maximum allowed length from the horizontal axle of the towing pin to the rear of the trailer 18 m. Maximum allowed length from the horizontal axle of the towing pin to the front of the trailer 2,04 m. |
 Trailer (actual trailer) | Maximum allowed length from the turning point of the front axles to the rear of the trailer 16 m. Maximum allowed length from the turning point of the front axles to the front of the trailer 2,04 m. |
 Other trailer | Maximum allowed length excluding the drawbar 12,5 m. |
Combination types
Combinations can be divided roughly into two types of combination. These are modular combinations and all the others not included in these.
Module combinations are structurally more than 22.00 m long full trailer combinations and over 16.50 m semi-trailer combinations.
Module combinations’ maximum length is 34.50 meters. More than 22.00 meters long combination must have ABS brakes.
Semi-trailer combination
Semi-trailer combination is drawn by a vehicle equipped with a tractor unit. Tractor unit is connected to semi-trailer. Semi-trailer pulling vehicle is often called tractor or prime mover. Semi-trailer combination is often called half or truck and semi-trailer is also called trailer.
Maximum allowed length of a semi-trailer combination
With a N3-class truck the maximum allowed length is 23 m.
(N3-class truck: total mass over 12 t)
With a N2-class truck the maximum allowed length is 16,50 m.
(N2-class truck: total mass at the maximum 12 t)
The maximum allowed weight of the 5-axle semi-trailer above is 44 tonnes.
The maximum allowed weight of the 6-axle semi-trailer above is 53 tonnes.
Full trailer combination
Full trailer combination is drawn by a truck equipped with ”pulling jaws”. Trailer is connected to the truck’s ”pulling jaws”. The official name of this combination is a combination of a car and the actual trailer. The combination is also known as full trailer or a full trailer combination.
The maximum allowed total weight of the combination depends on the number of axles. The maximum allowed weight of the 4-axle combination above is 36 tonnes.
The maximum allowed total weight of this 7-axle combination is 60 tonnes.
Full trailer combination can also be made of truck, dolly (apuvaunu) and semi-trailer. Dolly is a special structured center-axle trailer on top of which tractor unit is installed. Any semi-trailer can be connected to the tractor unit.
Combination extended with center-axle trailer
It is possible to connect a center-axle trailer to semi-trailer combination. Same size and weight restrictions apply to this module combination as for the modular full trailer combination. This combination’s unofficial nickname is spoon – fork due to its unpleasant tendencies when it is slippery. Same restrictions apply to this module combination as for other module combinations.
The maximum allowed weight of the 8-axle combination above is 64 tonnes.
Combination extended with semi-trailer
It is possible to connect to the first semi-trailer of semi- trailer combination a second semi-trailer. In this case, a tractor unit should be installed in the first semi-trailer. This combination haven’t been for long in Finland and it has established yet a nickname. The combination is called B-train or link in Sweden. (Original pictures by SKAL, edited by LM).
The maximum allowed weight of the 8-axle combination above is 64 tonnes.
Longer and heavier HCT-trucks
HCT stands for High Capacity Transport. It is an internationally established term for combinations longer or heavier than allowed in road transport, which, however, are not considered as special transport.
The greater length or weight of HCT shipments results from a larger than normal amount of goods. For example, a HCT combination can carry two 45′ containers, and a HCT log truck can carry a 25 percent larger timber load than a conventional log truck.
For example, an HCT truck can consist of a combination of two semi-trailers and a truck (pictured above), with a length of almost 32 meters.
The maximum allowed weights of combinations
| Combination | Tonnes | |
|---|---|---|
| a | A combination of a truck and a center-axle trailer | 50 |
| b | A combination of a truck and a semi-trailer, a truck and a trailer or a truck and multiple trailers | |
| b.1 | 4-axles | 36 |
| b.2 | 5-axles | 44 |
| b.3 | 6-axles | 53 |
| b.4 | 7-axles | 60 |
| b.5 | 8-axles | 64 |
| b.6 | At least 8-axles, if at least 65% of the mass of the trailer or of the total mass of the trailers is applied to axles fitted with twin wheels | 68 |
| b.7 | 9-axles | 69 |
| b.8 | At least 9-axles, if at least 65% of the mass of the trailer or of the total mass of the trailers is applied to axles fitted with twin wheels | 76 |
| b.9 | 10-axles | 74 |
| b.10 | At least 11-axles | 76 |