horse. Amish farmers employ chemical pesticides, chemical fertilizers, and artificial insemination of cows. The Ordnung is the guide to community standards, and a doctrine that defines sin. For example, the four Old Order Amish communities of Allen County, Indiana, are more conservative than most; they use open buggies, even during the winter, and they wear black leather shoes even in the hot summer. Restrictions are not meant to impose suffering. Disabled people are allowed to use motorized wheelchairs; electricity is allowed in the home for medical equipment. Those who break the rules may be given many months to resolve the problem so that they can remove electric wiring from a new house. Although most Amish will not drive cars, they will hire drivers and vans, for example, for visiting family, weekly grocery shopping, or commuting to the workplace off the farm, though this too is subject to local regulation and variation. The practice increases the geographic reach of the Amish, and decreases isolation: a horse can travel only about , and it must rest for a considerable period, restricting the Amish to a radius of from home. Moreover, a horse and buggy can only sustain over an extended distance, and thus is impractical for emergencies. The Amish are permitted to travel by bus and train in order to shop, work at markets, and reach more distant destinations. Regular bus service between Amish communities has been established in some areas. The Amish are not permitted to travel by airplane as air travel is regarded as too modern. The Old Order Amish tend to restrict telephone use, as it is viewed by some as interfering with separation from the world. It intrudes into the privacy and sanctity of the family, and interferes with social community by eliminating face-to-face communication. Amish of Lancaster County use the telephone primarily for outgoing calls, with the added restriction that the telephone not be inside the house, but rather in a phone "booth" or small out-building placed far enough from the house as to make its use inconvenient. These private phones may be shared by more than one family. This allows the Amish to control their communication, and not have telephone calls invade their homes, but also to conduct business, as needed. In the past, the use of public pay phones in town for such calls was more common; today, with dwindling availability of pay phones because