The Mercedes-Benz Citaro is the most successful urban regular-service bus of all time. Since series production first started in 1998, over 31,000 have been built. In that time, it has acquired international renown, having entered service in almost all major European cities and far beyond. First unveiled at the UITP Congress in Stuttgart 1997, the Citaro urban and rural regular-service bus has gone from strength to strength.
Unrivalled range of low-floor regular-service buses
One of the ingredients for success is the wide-ranging model line-up. The portfolio of the world’s best-selling low-floor regular-service bus comprises 28 different design variants. An ingenious modular system forms the basis for this unique variety of models. It ranges from the compact Citaro K measuring 10.5 metres in length to the CapaCity, a four-axle, 19.54 m-long, high-capacity articulated bus that was derived from the Citaro platform. This unrivalled model range enables the Citaro to cover the complete spectrum of transportation requirements of local public transport companies operating urban and rural regular-service bus routes.
Design and functionality of the Citaro perfectly matched
The hallmark features of the Citaro model family give them an unmistakable appearance. From the front end with its characteristic A-zero pillars to the three-dimensional styling of the back end with its V-shaped rear window, the Citaro has a highly distinctive design. It is also remarkable for its excellent functionality, with smooth, rounded exterior surfaces that are easy to clean and sidewalls made from lightweight aluminium, divided into segments to keep repair costs low and minimise downtimes. Apart from the front-end flap, the corner sections including the headlamp housings fold open too – making the entire front end easily accessible for maintenance work. All other maintenance points on the Citaro are easily accessible too.
The passenger compartment has revolutionised regular-service bus interiors
When passengers step aboard the low-floor bus, they are greeted by the lettering of the Mercedes-Benz brand. With its side-mounted cantilever seating and curving grab rails, the passenger compartment of the Citaro has revolutionised the interior of all urban buses, providing a role model for the entire vehicle segment. Form and function are in perfect harmony.
Comfortable independent front suspension
The Mercedes-Benz Citaro also distinguishes itself with qualities that cannot be seen, but can certainly be felt. Amongst other things, it boasts an independent front suspension, whose benefits include excellent straight-line stability, less influence on the steering from the road, a substantial saving in weight, lower unsprung masses, and improved handling and comfort characteristics in general. As a consequence, the Citaro offers a remarkably safe, composed and comfortable ride by low-floor bus standards. It also benefits from a large wheel turning angle, resulting in a small turning circle.
The unprecedented success story of the Mercedes-Benz Citaro
With over 31,000 units built, the Citaro already ranks as one of the top-selling bus models ever. No-one could have imagined such phenomenal success when Mercedes-Benz surprised the delegates at the 1997 UITP Congress in Stuttgart with the revolutionary Citaro. Even today, many in the urban bus segment still try to emulate its exemplary concept: passenger-friendly low-floor technology, a bright passenger compartment offering an excellent view through high windows, wall-mounted passenger seats in cantilever design without any floor supports to get in the way and with attractively designed, curving grab rails on the side – these were just a few of the key strengths of the new Mercedes-Benz Citaro, which it still retains today.
From the very start, fleet operators reaped the benefits of powerful, economical engines and of the Flexibly Programmed Control electronics system based on a CAN data bus architecture. This replaced miles of wiring and around 300 electronic, electrical and electromechanical components. The Electronic Braking System (EBS), disc brakes all round, ABS and side impact protection were likewise included from the outset to provide the greatest possible safety.
Continuous improvements down to the last detail
A key element in the Citaro’s recipe for success is its ongoing development. In autumn 2005, Mercedes-Benz took the model range to new heights with the second generation of the Citaro. It was kick-started with the debut of the new Citaro LE (low entry). This already included many of the modifications which were then incorporated into series production for all Citaro models in spring 2006. The front section, rear, interior and driver’s area all underwent a thorough overhaul, while the independent front suspension was also introduced for the first time.
Quick advance from Euro II to EEV
During its production, the Mercedes-Benz Citaro ran through almost the full scale of Euro emissions standards. At its premiere in 1997, the in-line six-cylinder engine with a Euro II rating represented the state of the art in emissions technology. The 2001 model version of the Citaro was powered by Euro III engines. Alternatively, the Citaro was already available with a CRT particulate filter which undercut the Euro IV particulate limits. In 2000, Mercedes-Benz presented the Citaro with natural-gas drive. This fulfilled the Euro IV emissions limits, and became available with the voluntary EEV (Enhanced Environmentally-friendly Vehicle) rating in 2002. The Citaro could also be specified with the German “Blue Angel” environmental certification in both its natural-gas and diesel variants.
Since 2006, diesel engines with the SCR emission control system have been fitted to meet the Euro IV and Euro V emissions standards. This BlueTec diesel technology produces a clear reduction in pollutant emissions, and enables fuel consumption to be lowered by a considerable margin at the same time.
Particulate emissions can be cut further by adding an optional particulate filter. This combination allowed the diesel engines to meet the voluntary EEV standard – and since spring 2010 they have been able to do so by means of internal engine measures alone, without the need for a particulate filter.
Pioneer of alternative drive systems
Apart from diesel-engined models, the range also includes the Citaro CNG with natural-gas drive. Between 2003 and 2010, 36 Citaro fuel-cell-powered buses run by twelve transport operators in countries as far apart as Iceland and Australia, covering three different continents, clocked up over two million kilometres of rigorous daily operation: it was the Citaro which first demonstrated the viability and everyday practicality of a genuine local public transport operation with zero CO2 emissions. Since 2010, the range of cutting-edge alternative drive versions has been extended by the Citaro G BlueTec Hybrid with diesel-electric hybrid drive, as well as an initial small-scale series of the rigid Citaro fuel-cell hybrid bus.
The Citaro G BlueTec Hybrid is a stepping stone en route from the diesel engine to series production of the fuel cell as a means of powering vehicles. With its serial diesel-electric hybrid drive, it enables extremely quiet, emission-free driving for several kilometres at a time.
The new Citaro FuelCELL Hybrid unveiled in early summer 2009 completes the final step to emission-free driving. Its avant-garde vehicle concept takes elements from tried-and-tested Mercedes-Benz fuel-cell buses and the diesel-electric Citaro G BlueTec Hybrid, and fuses them together with technical advances to create a new trailblazing drive system. The platform is provided by the Citaro.
The Citaro FuelCELL Hybrid emits no pollutants whatsoever and hardly makes a sound as it glides along.
Highly sophisticated production as a quality safeguard
The manufacture of the Citaro is just as pioneering. The bodyshells are assembled in the Bodyshell Centre at the Mannheim bus plant. The Citaro bodies are then primed in the Mannheim plant's cathodic dip priming facility to ensure complete corrosion protection with no gaps. The bodyshells then either move straight to final assembly in Mannheim or are transported to the assembly plants in Ligny-en-Barrois in France or Neu-Ulm to be turned into finished vehicles. Despite an urban bus's tremendous complexity, the error rate has been tending towards zero for a long time now. Nevertheless, before being delivered to the customer, every bus is put through its paces under practical conditions in real traffic on a route measuring around 100 kilometres in length.
Milestone buses supplied to Germany, Austria, Spain and Sweden
All things considered, it is little wonder that the Mercedes-Benz Citaro continues to break one record after the next. The 1000th Citaro left the factory just two years after production started, Citaro no. 10,000 rolled off the assembly line at the end of 2004. In early 2008, Mercedes-Benz delivered its 20,000th Citaro, followed by the 30,000th in summer 2010.
The Citaro can be seen operating throughout Europe’s major cities, on rural-service routes in Germany, on the tropical island of La Réunion, in Japan, China, Mexico and Australia, and even transporting pilgrims in Lourdes. In the Romanian capital of Bucharest alone, around 1000 are in service. The Citaro transports millions of passengers every day in Europe and far beyond. It forms the backbone of urban public transport, and even bridges the gap to the train in the guise of the CapaCity high-capacity bus.
Numerous special versions
The Citaro’s modular construction paves the way for numerous special versions. So, it is not unusual to see the Citaro in action as a specially converted fire-service command centre, police bus, mobile television studio or high-capacity rescue vehicle. In Poland, a Citaro is travelling around as a mobile energy advice centre. In Hanover, the 101 Citaro buses in the special livery of Üstra, the public transport operator, are as eye-catching as ever. They were put into service on the occasion of the World Exhibition in 2000 and given an unmistakable finish both inside and out.
The Citaro has even made it into the Guinness Book of Records as the world’s largest ambulance: in autumn 2009, a high-capacity rescue vehicle based on the Citaro G was deemed by adjudicators to have treatment and transport capacity for 123 people. The record-breaking articulated bus is already the third high-capacity ambulance for the sheikdom of Dubai. Apart from this trio, there are more than 300 other Citaro models also operating in Dubai. They are equipped with special insulation, special glass as well as air showers in the entrances to prepare them for the extreme heat in the Middle East sheikdom.
Platform for innovative transport systems
The Citaro is also typically used as a platform for innovative transport systems. Take, for example, the articulated Citaro GÜ buses that are operating as “road trains” in the town of Mittweida in Saxony. The buses were brought in to replace a discontinued rail link and boast a somewhat unusual specification. Passengers sit on coach-style seats which are arranged face to face, and on-board facilities include a bistro area, a toilet and space for carrying bicycles.
The 20 Bus-Way vehicles based on the Citaro G that are operating in the French city of Nantes are no less spectacular. These natural-gas-powered vehicles have their own lane. They feature an attractive, highly individual design, with side panelling that extends above the roof line, double-glazed side windows and covered wheel arches on the rear axles. Inside, LED spotlights divide the interior into two differently coloured areas. Uplighters on the window pillars, a maple wood central ceiling, grab rails made from ground stainless steel and dark blue seats give the passenger compartment its distinctive design. The driver’s cab is separated from the passenger compartment.
The “Metrobüs” BRT system in Istanbul, Turkey
The implementation of a BRT (bus rapid transit) system in Istanbul, Turkey, is no less ambitious. The “Metrobüs” travels along a 40.6‑kilometre route in dedicated lanes. At peak times, the buses run at very short intervals of less than half a minute. This results in passenger numbers of around 750,000 a day. The Mercedes-Benz CapaCity – the oversized, four-axle (19.54 m) high-capacity articulated bus derived from the Citaro – serves as the basis for this BRT system. 250 of them are already in operation there. Not only does the CapaCity offer a high transport capacity, it also achieves an exceptionally high average speed by urban bus standards of 40 km/h – all combined with extremely attractive lifecycle costs too. A trip aboard the Mercedes-Benz CapaCity in Istanbul is also highly popular due to its low-floor design and because the vehicles are air-conditioned.