Some countries such as Australia[1] have special routes and timetables exclusively used by students, but still run by public transportation services.Parental transport of students in the family automobile, sometimes termed the "school run", is increasing due to perceived hazards to unaccompanied children.[3] In Argentina, although most students either walk, are driven by parents, or take regular public transit to school, many of them use private buses carrying an identification and authorization[4] of government in each city.Parents pay the van owner a monthly fee to carry their children back and forth from school.[clarification needed] In Australia, students who live in outer suburban or rural areas often travel on public buses and trains or on special routes provided by private bus companies.[8] In Canada, student transport is generally handled in much the same way as it is in the United States: the yellow school bus.As population migration trends internal to New Zealand have favored the growth of cities, it is an increasingly smaller minority of students who are served by school buses.Parents, acting as chauffeurs, are filling this gap, with multiple negative consequences (e.g. productivity losses for the New Zealand workforce, increased vehicular traffic interfering with commercial or industrial traffic well into the work-day, increased carbon footprint, diminished development of transport self-management skills in early teenagers, dangerous concentrations of hectic motoring near congested school entrances at school start-times, etc).The matter occasionally surfaces in the New Zealand media, but making free school busing the norm is usually dismissed as another example of American-style thinking.In Auckland, New Zealand, as at November 2007, one hundred schools were running 230 walking buses with over 4,000 children and 1,500 adults participating.In the United Kingdom, there are concerns about children's safety after they have alighted from conventional buses used for student transport.[33] As a result of this, over the past decade, starting in around 2000,[34] the talk of and introduction of dedicated, yellow student-specific school buses has been widespread.[36] North American-style 'yellow' school buses (built by European manufacturers) are being introduced by First Student UK and My bus.The first walking bus in the United Kingdom was introduced in 1998 by Hertfordshire County Council and used by students of Wheatfields Junior School in St Albans in 1998 [37] In the United States, purpose-built school buses are the primary means of student transport, almost always provided without charge to families.Each year, school buses provide an estimated 10 billion student trips in the United States.Approximately 40% of school districts in the United States use contractors to handle the function of student transport.