highways are separated into three categories: all-access valtatie ("main road"), limited-access moottoriliikennetie ("motor traffic road") and finally moottoritie ("motorway"); the latter two are marked with green signage, while valtatie signage is blue. While most of the network is all-access road, of it is motorway, and is limited-access road. The access is limited to motor vehicles faster than 50 km/h, thus excluding pedestrian, bicycle, moped or tractor traffic; furthermore, towing is not allowed. Limited-access roads are generally similar to motorways, but do not fulfill all the technical requirements, such as several lanes in one direction or separation of opposite directions. Limited-access roads are usually built because the local population density is too low to justify a motorway. Often space has been left during construction for an eventual upgrade to a motorway. Limited-access roads also function as feeder routes for motorways. The general speed limit on main roads and limited-access roads is 100 km/h (summertime) and 80 km/h (wintertime). On motorways the speed limits are 120 and 100 km/h respectively. Especially during winter the speed limits can be changed due to weather conditions. Germany: Kraftfahrstraße A Kraftfahrstrasse (German for "motor-power road", also colloquially called Schnellstraße, literally "fast road") in Germany is any road with access limited to motor vehicles with a maximum design speed of more than , excluding pedestrian, bicycle, moped or tractor traffic. Oversized vehicles are banned. The construction of transregional Kraftfahrstraßen highways (Autostraßen) rank below the standard of German autobahns. With regard to the general German speed limits, on roads with lanes separated by a median or with a minimum of two marked lanes per direction, an advisory speed limit (Richtgeschwindigkeit) of applies. At-grade intersections are admissible, regulation at junctions is usually provided by traffic lights or roundabouts. U-turns and any deliberate stopping are prohibited. Kraftfahrstraßen are out of bounds to pedestrians, except for special crosswalks. Hungary: Autóút Expressways in Hungary are called Autóút (Auto/car road). They are mostly dual carriageways. The main difference between Hungarian motorways and expressways is, that they are more cheaply built with narrower width and often undivided. Maximum speed limit is reduced to 110 km/h for vehicles under 3.5 tons, and 70 km/h for vehicles over 3.5 tons. In Hungary there are multiple types of dual carriageways. One part is almost identical with motorways, but the driving lanes are narrower. Parameters of a 2+2 lane dual carriageway off-habitat area: Total width of road: 25.60