Bus dimensions, weight & axle load

A bus must stay within the limits of the Danish Dimensions Order (Dimensionsbekendtgørelsen) for width, height, length, total weight and axle load. The figures below are the most commonly used — but the exact weight/axle-load provisions should always be verified against the order in force before they are used in a legal context.

Det tilladte akseltryk afhænger ikke kun af den enkelte aksel, men også af afstanden til nabo-akslen. Sidder to eller tre aksler tæt sammen, kaldes de en akselgruppe (tandem = to aksler, tridem = tre aksler), og den samlede vægt fordeles på et mindre stykke vej. Derfor sætter Dimensionsbekendtgørelsen et loft for hele gruppen, der er lavere end summen af de enkelte akslers grænser — og loftet stiger, jo længere der er mellem akslerne.

• 01The shorter the spacing, the lower the total permitted pressure on the group (to spare the road).
• 02A tandem group on a bus typically has a combined limit dependent on axle spacing — look up the precise interval in the regulation.
• 03A 3-axle group has a higher combined limit than a tandem, but still lower than 3 × single axle.
• 04Lifting axle (liftable axle) does not count when raised — but then the weight is borne by the other axles, which may then exceed their limit.

A bus must be able to turn within a circle ring: it must be able to drive 360° around between an outer circle with radius 12.5 m and an inner circle with radius 5.3 m, without any part of the bus reaching beyond the ring (UNECE Regulation No. 107, reproduced in the Dimensions Regulation). It is this requirement that actually limits how long a rigid (non-articulated) bus may be, and why long buses have steerable rear wheels or are articulated. When entering the turn the bus's foremost, outermost point may at most swing 0.6 m beyond the outer circle.

Overhang is the part of the bus that sticks out in front of the front axle (front overhang) and behind the rear axle (rear overhang). A long rear overhang makes the rear end swing out to the opposite side when you turn — 'fishtail' — which is a classic hazard when departing from a bus stop and when turning right. UNECE R107 limits the overhang in relation to the axle distance, so the bus can comply with the turning circle. This is also why the rear overhang cannot simply be made arbitrarily long to get more seats.

The registration certificate and type plate indicate the vehicle's technically permitted total weight and the technically permitted axle loads — what the manufacturer has approved the bus for. The legal limit on the road is the lower of two numbers: the manufacturer's technical limit AND the Dimensioning Regulation's limit. A bus can thus be technically approved for more than it is legally allowed to weigh on Danish roads — it is always the lower value that applies.

• 01Registration certificate field F.1/F.2 — technical and legal total weight.
• 02Type plate in engine bay/door frame — manufacturer's permitted axle and total weights, line by line.
• 03Den lovlige grænse = laveste af teknisk grænse og bekendtgørelsens grænse.