Obviously not all loads that need to be moved by road are typical or uniform. It is clearly beneficial when they are, however often the abnormality of loads might be unavoidable. Something like a modular building might be considered an abnormal load.
You might have a requirement to transport an abnormal load. The nature of this load might be very idiosyncratic, i.e. abnormal. For example, you might require t transport a modular building, or a load that is particularly heavy.