The battle for the maximum allowed axle loads will probably never end. As a normal car driver, one can easily see that generally, only three axles belong on the trailer of a real 40-tonner. If they have only two axles, they have to be satisfied with a gross weight of 36 tons. If then you equate the 40 tons with, e.g., 30 VW Golfs and compare their entire tyre contact area with that of the 40-tonner, you will know why the trucks, particularly through impact strain, ruin the road surfaces more than motor cars do.

At the moment, the question of permissible vehicle-overall-length, is especially relevant. It used to be, e.g., in 1935, 22 meters, which applied to the usual articulated vehicles with two trailers. If one assumes the maximum possible perfomance of (by no means always) 110 kW (150 hp), it is easy to imagine how the trucks crept up the hills, particularly as, at that time, the motorways were mostly still under construction. The so- called Cabin-Over-Engine (or flat-noses, as they were also known), only appeared in the 1960's and were limited to an overall length of 18,75 meters.

Why the is question particularly relevant right now? This is because a few federal states (Germany) are taking part in trials, to increase the overall length by adding an additional trailer to up to 25,25 meters, thereby increasing the maximum tonnage to 60. At least in Germany, that would only be a -road-surface-friendly - 44 tons of permissable gross weight, thus giving the roads a little breathing space. By the way, in the USA they have a similar system, where larger units may be operated, but only in certain states. The advantage: less consumption per ton of cargo, the disadvantage: for some roads they are too unwieldy.

Even though, in view of the roads becoming smoother, the tractor and trailer have moved closer to each other, the semi-trailer remains the more economical and universally more usable vehicle. You should have a look at the movement- and motion studies of certain manufacturers, how one manages to get through the narrow factory lanes, forwards and in reverse. If the driver has to shift his position right to the front, and possibly has his bed overhead, the volume needed for the cargo takes power over the whole construction.

In so-called volume-cargo-units, the legal height is fully exploited. For this, the frame must be lowered to below the upper tyre-edge, of course, not with normal tyres but ones with a lower profile. Indeed, the radial-type truck tyre differs from the motor car tyre only as far as load-carrying capacity and the enormously high air-pressures are concerned. You may be able to imagine, the construction problems which arise in view of this type of lowering, considering that the rigid axle is still preferred.

Could it be, that in future, not only the fans of particularly low-lying cars, but also the truck drivers, will have pay attention to humps and bumps in the road? That almost brings us the subject of truck-tuning. Have a look at the variety of aluminium rims, shown at a utility vehicle exhibition (see above picture). Granted, it's not as many as at the Motor-show in Essen, indeed one is still surprised. After all, the vehicle is primarily, supposed to be economical. What really knocks one down, is sitting in a cockpit with leather seating. N.B., The seats don't come from an exclusive tuner, than can be had, together with a bigger engine, directly from the factory for the paltry sum of €15,000 extra.

Apparently, the boss himself does the driving here. These features are unthinkable for larger vehicle-fleets. Although, there is also here, no lack of comfort. Refrigerated compartments and plenty of storage space, sometimes even accessible from the outside, like the car-boot. In addition, auxilliary heating and any electronics that can be imagined. The only thing the driver doesn't have, is space. On the other hand, comfort is necessary when one considers the sometimes very long waiting periods, possibly the whole weekend and that, parked at a boring and mostly congested motorway service-area.