When driving on main roads, which vehicles must use the hard shoulders where possible?

In Germany, traffic rules specify that certain slow-moving vehicles must use the hard shoulders on main roads where possible to ensure traffic flow and safety. This specifically includes agricultural tractors and machinery, as well as mopeds. These vehicles are generally slower than regular traffic, and using the hard shoulder helps reduce congestion and allows faster vehicles to pass safely.

Small-engine motorcycles are typically not required to use the hard shoulder, as they can maintain a speed that is generally more in line with regular traffic. Thus, their inclusion in the answer is not necessary for compliance with German traffic laws.

Understanding which vehicles are required to use the hard shoulder is important not only for following the law but also for enhancing road safety for all users. Selecting all relevant options ensures that all appropriate vehicles are accounted for in maintaining smooth traffic conditions.