is used to visually distinguish cycle ways from car lanes and footpaths. Standard black asphalt is also commonly used and some older cycle paths are made of the square tiles commonly used for sidewalks. On-road bike lanes On-road bike lanes in the Netherlands are marked by either a dashed line or a solid line: lanes marked by a dashed line may be used by motorists provided that they do not impede cyclists, while those marked with a solid line may not be used by motorists. Solid lines are interrupted on crossings to allow motorists to enter or leave the road. Car parking is never allowed in either type of lane. Bike lanes are usually surfaced with red or black asphalt. The red colour has no legal meaning, it is there for visibility; the on-road bike lane is delineated by the solid or dashed line by which it is separated from the roadway. National guidelines advise a minimum width of 1.25 m for cycle lanes. When a cycle lane is present on a road, cyclists are obliged to use it. Since 15 December 1999 mopeds are not allowed on cycle lanes. Fietsstraat (cyclestreet) A fietsstraat (cyclestreet) is a road where bicycles are considered to be the primary and preferred form of transport and where cars and other motorised vehicles are allowed "as guests". Designs vary, but most examples incorporate red asphalt and have a speed limit of 30 km/h. Fietsstraat streets exist mostly in residential areas where low-traffic roads exist anyway. A fietsstraat was in most cases originally a road that had low-traffic volumes beforehand and was therefore easily converted. They are an important type of infrastructure which makes Dutch towns and cities safer for cyclists. They can also be used for route separation to enable cyclists to avoid busier roads and have direct routes into and through towns. The unravelling of modes In Dutch towns and cities, many bike-only routes are not alongside the roadway, nor do they run close by and parallel to major car routes: rather, cycle routes are often completely separate from motor vehicle routes. In many cases, dedicated bike routes are far more direct than the local car routes are to common destinations, such as town centres. This complete separation of bicycle routes from motor vehicle routes is called the unravelling of modes and is an important feature of modern Dutch urban design and traffic management.