The next time you see some perfectly drown circles on the ground near the mines, do not blame it on aliens first. It is not a phenomenon at all and it could possibly done by one of these trucks, The MT-240 truck by EFT.

ETF developed a unique steering system.

All wheels are steered at low to medium speeds reducing tire wear, while at higher speeds the last two axle lines gradually change to nearly rigid resulting in better stability.

ETF trucks are equipped with a special speed-proportional steering system.

At very low speeds, such as when spotting the loader, the system requires only two turns from lock to lock. The whole system works automatically without interference from the operator.