> Maximum length of a truck with a semi-trailer in Europe is 18.75 meters. Some countries have some exceptions, but generally that is the rule. In order to use the maximum of this length for the cargo the tractor unit has to be as short as possible. The best way to achieve that is to mount the cabin over the engine.
That's it. Headline with a question and that one paragraph. This article to me is an example of why articles on the modern web are bad. All the rest is there to keep you on the page longer and get better SEO.