in the Hamburg Wadden Sea National Park are also in the state's proper. In 2006, the city of Hamburg installed a pedestrian guidance system in its centre. Public transport Public transport in Hamburg consists of buses, subways and light rail, commuter trains, car pool services, taxis, services for senior citizens and people with disabilities. The Hamburger Verkehrsverbund (HVV) manage and coordinate the public mass transport with busses, ferries and trains for the Public Transport Authorities—the three states: Hamburg, Lower Saxony, and Schleswig-Holstein, and several districts. The 35 operating cooperations provide the transport services and some of the customer services. Buses Major company for the public bus services is the Hamburg Hochbahn AG (HHA) with more than 100 lines and driven per day. Another main operator is the regional and city bus company Verkehrsbetriebe Hamburg-Holstein (VHH), operating many own lines (especially in the outer districts and on outbound lines) and sharing services with the Hamburger Hochbahn on several lines. Both companies handed over small parts of their services and some lines to subcontractors and subsidiaries such as Jasper or Süderelbe-Bus. Since 2001, the HHA uses a passenger information system at several bus stops to inform the passengers. Long distance bus lines start at the Hamburg Central Bus Station (German: Zentraler Omnibusbahnhof Hamburg). In 2007, there were more than 450 lines departing per week with travel destinations in 27 European countries, e.g. Denmark, Poland, and Russia. Alternative propulsion of buses Since 2003, Hamburg has deployed nine hydrogen fuel cell buses as part of a trial to access the long-term practically of hydrogen fuel cell vehicles. Those modified Mercedes-Benz Citaro buses were retired between 2008 and 2010. They were replaced in 2011 by four new hydrogen fuel cell buses, again being delivered by Mercedes-Benz. In 2014 another 30 hybrid buses were delivered, including the 10 plug-in hybrid buses mentioned above and 15 articulated buses of the type Volvo 7900. At the same time two fuel cell powered Solaris Urbino 18 entered service. In 2016 three electric Solaris New Urbino of the new generation were added to the Hochbahn fleet. At the same time the Verkehrsbetriebe Hamburg-Holstein (VHH) received 20 hybrid buses from Volvo and two fully electric buses from Italian manufacturer Rampini. Together with the subsidiary companies 68 buses with alternative propulsion are in service in Hamburg in total. They e.g. run on the line 109 (Hamburger Hochbahn) - that was designated as