For instance, many Dutch towns and cities have a "soft" green core that is only accessible to cyclists and pedestrians. Therefore, while drivers wishing to cross the town may have to take a lengthy detour via a ring road, cyclists can take a direct route through the town centre. Other cycle routes work similarly. On a small scale, short sections of cycle path can provide a short cut between streets that cars cannot take, while on a larger scale entire streets are sometimes converted to cycle paths to provide more room for cyclists and discourage the use of motorized vehicles. Free-running cycle paths also exist for recreational purposes, in parks and in the countryside. These are usually bidirectional. Countryside On busy and important routes, cycling facilities in the countryside are similar to those in the cities. Cycle paths are made where possible, and cycle lanes otherwise. If the available space is too limited even for a cycle lane, for example when a road passes through a village, speed-reducing measures are usually taken to ensure that the difference in speed between cyclists and motorists is tolerable. Highways and "provincial roads" (main roads for which a province is responsible), are usually fitted with separate cycle paths. Motorways, on the other hand, rarely have cycling facilities associated with them. If a cycle path is bundled with a motorway it usually lies at a relatively large distance from the road, outside the traffic barriers and noise barriers. Apart from these utility paths and lanes, many recreational paths are available in the countryside. Their pavement varies from gravel through asphalt. Crushed seashells are a popular variant. Snelfietsroutes (Fast bike routes) A bicycle-only route intended for cycling longer distances for practical reasons such as commuting or for sport and exercise can either be called a snelfietsroute (fast bike route) or a fietssnelweg (cycle highway). Some characteristics of these cycling routes mentioned by governments (both national and local) and traffic experts are bi-directional paths with recommended uni-directional lane widths of 2 metres and minimum widths of 1.5 metres; very level and straight stretches (i.e. few ups and downs, curves or turns); the absence of traffic lights and level crossings with motorised traffic; and superior pavement quality. Cycling interest groups and national and local governments advocate such routes as being a solution for the further reduction of vehicular traffic congestion: this is because, as cyclists can achieve higher