Forward-pointing technology for the Citaro urban bus
Made-to-measure Cito midibus
The Travego follows the O 404
The 1990s brought a great many changes in the brand landscape among Europe’s bus and coach manufacturers. As the year 1994 progressed, the signs of what would come to pass in early 1995, 100 years since Carl Benz invented the bus, became increasingly clearer: the then Daimler-Benz AG would take over the Setra brand, spin off the Mercedes-Benz Bus and Coach unit and join the two brands to create the subsidiary EvoBus GmbH.
Behind this move was the search for a new approach to the business. In the existing constellation, for years the buses and coaches with the star had been unable to put themselves on an economically sound basis. And since the first-rate brand Setra of Karl Kässbohrer Fahrzeugwerke was not doing too well either, the probably once-in-a-lifetime opportunity resulted to bring the two tradition-steeped companies together under one roof: contribute the different strengths of each brand, attack the weaknesses of each brand – that could lead to success.
And so it was. After a relatively short time EvoBus moved into the black and was doing certain things differently than both the group in Stuttgart and the former family-owned company in Ulm. Part of what was different were the synergies which began with a well-thought-out production system: manufacture of the bodyshell for all buses of both brands, including cataphoretic dip priming, at the Mannheim factory; transfer by rail directly from Mannheim to Neu-Ulm, to the plant which was newly built at the start of the 90s. Final assembly and painting there – and there’s your bus. Ten years after the establishment of EvoBus, only the Citaro was being manufactured entirely in Mannheim; only the variants for France were produced at the French plant in Ligny.
The bus plants in Turkey played a role of their own. They were a part of the group, and buses and coaches were built there both for the home market and for the surrounding countries, including the Tourismo for Western Europe. Another factory in the Czech Republic supplied bodyshell parts. Mercedes-Benz chassis for touring coaches meanwhile are produced in Spain and shipped out to the entire world from there.
Synergies also related to the products. The promise stood to preserve the brand identity of Mercedes-Benz and Setra. For this reason the buses each have their own distinctive appearance, and technically and in the area of appointments and product lineup they have their own distinctive profile. But where the design of major components, electronics or safety components is concerned: these are areas in which quality, function and therefore development and testing effort and expense play a big role. Things like this can be produced for both brands together. Safety, for example, is indivisible.
The first new bus created under the EvoBus umbrella was the O 550/Integro rural-service bus in 1996, the first bus with the star that bore a name in addition to the bare design designation. It had a high percentage of Setra in it and was based on the
S 315 UL from the current MultiClass. With the Integro, Mercedes-Benz quickly filled a gap in its range: in the mid-1990s a rural-service and excursion bus with fresh looks which presented a contrast to the stern and square-faced standard buses was lacking. Like many a compromise, the Integro turned out to be a long-running success.
With time it matured into an entire family, with a long variant exceeding twelve meters in length, and a raised-floor bus which could better address the requirements on a bus used to a large extent for excursion or even touring service.
In 2006 Mercedes-Benz finally completely redesigned the Integro. With three different lengths on two axles (Integro and Integro M) the two-door specialist now covers the entire spectrum from short regular-service routes in suburbia to long-distance interurban use.
The customer can choose from a large number of special equipment items and spec out the vehicle precisely for his purposes. The facelift also brought a 140 millimeter extension to the front end, which is to the advantage of the driver’s area and the entrance as well as the optionally available tour guide’s seat. Altogether, the new exterior width of 2.55 meters makes for even greater spaciousness.
As to the engines, SCR units complying with Euro 4 and Euro 5 made their arrival. As standard, Mercedes delivers the Integro with the horizontally installed in-line six-cylinder OM 457 hLA developing 299 hp. On request, a variant with 354 hp also is available; it is standard equipment for the three-axle Integro L (15 meters long).
The name Integro was agenda in two respects: the new bus integrated rural-service bus and excursion bus in one model. And it was a symbol of the integration of the Mercedes-Benz Bus and Coach unit and Setra. Endowed with many Setra genes, the Mercedes-Benz Integro did not stand for an entirely new bus from the new company, EvoBus. Mercedes-Benz would present that a year later.
The Citaro arrives with forward-pointing technology
Its very first appearance in 1997 at the UITP Congress in Stuttgart caused quite a stir: seldom was a new urban regular-service bus the subject of so much interest and attention as the prototype of the Mercedes-Benz Citaro at the world congress of public transport operators. The Citaro as a completely new design with forward-pointing technology, and looks which were no less extraordinary, and as a complete in-house development, rang in the end of the conventional standard urban regular-service bus as built successfully by Mercedes-Benz in the form of the O 305 and O 405 for more than 30 years.
The courage to make a fresh start with the Mercedes-Benz Citaro and many ideas of one’s own went down outstandingly well with transport operators and passengers. So well that the Citaro celebrated a rare jubilee in autumn 2004: at the FIAA bus and coach show in Madrid in October 2004 the 10,000th bus of the model series was handed over to a customer. The Citaro was thus sticking hard on the heels of its square-jawed predecessor, the O 405.
Indisputably, the Mercedes-Benz Citaro is a milestone in bus development. In 1997 it surprised people with a unique concept for passengers and operators. Since the premiere of the Citaro, passengers can take pleasure in the thorough implementation of a passenger-friendly low-floor technology, in a bright and friendly interior with much headroom, best visibility, effective climate control, side impact protection, optionally available electrically powered pivot-and-slide doors, and an equally sensitive and effective Electronic Braking System (EBS) with disk brakes all around.
The operators, on the other hand, profited from the start from engines which were as economical as they were powerful; from the flexibly programmable control system (FPS), an electronic system based on a CAN databus; which substitutes for kilometers of cable and thousands of trouble-prone electronic parts; from a design which lends itself to easy maintenance and cleaning; from the cantilever-type wall-side seat supports without inconvenient legs; from the full utilization for interior space of the length limit of twelve meters for solo buses which existed then and the maximum permissible width of 2.55 meters; as well as from the modular element design as prerequisite for numerous variants.
The developers and designers packaged this and much more in a beautifully shaped and practically designed body, carefully and consistently styled, from the shape of the headlamps, characteristic of the brand, with white turn signal glass, to the curved, color-contrasted A-pillar with the harmonious transition to the roof and the large windshield with integral destination indicator, through to the rear window, which incorporates the bus number indicator and raised tail lights and turn signal lamps. In short: an urban bus all of a piece, a trailblazer, technically and visually.
After the market launch in 1998 the new Mercedes-Benz Citaro quickly gained acceptance in Germany and throughout Europe. In the startup year it already reached a production figure of 341 units for ten European countries from Norway to Spain. At the beginning of the year 2000 Mercedes-Benz delivered the 1000th Citaro. The rapidly rising output figures were attributable among other things to the effective modular system: The twelve meter long solo bus soon was joined by the articulated bus, the rural-service variant Citaro Ü and a first chassis. Additional variants joined the fold in rapid succession. By then well over 2000 Citaro were leaving production in Mannheim each year, with prospects for more.
The technical evolution of the Citaro progressed no less quickly. In the spirit of continuous product improvement, during the past years numerous improvements have entered into the series. The first were details that further enhanced the ease of servicing and repair. Examples of this are the separate maintenance flap, which permits convenient daily visual checking of the fluid levels, and the radiator flap with enlarged air intake surface, redesigned for easier maintenance. Further new features included improved access to the engine compartment through a fold-open rear panel, the intercooler that could be swung out for easy cleaning, and much more.
Numerous improvements in the interior
Numerous improvements also were made to the interior, ranging from a new cover for the radiators in the side walls to further seating variants. A more variable design of the bus was also possible. For instance, an engine mounted longitudinally on the left side of the bus, as an optional extra, permitted creating both solo and articulated buses with a low floor extending all the way to the rear.
In the same way, over the years the economy of the Citaro also could be further improved. The shift strategy of the ZF automatic transmission meanwhile had been refined; five shift programs were available. Compressed air tanks made of aluminum instead of steel cut weight. A new brake management system permitted even more sensitive deceleration The destination display is extremely flat, very readable, easy to operate and service. It is no secret that the entirely new Citaro with its comprehensive equipment initially posed problems to production. But these difficulties were overcome many years ago.
The Mercedes-Benz Citaro long since had grown into an extensive family of models which served the entire public transit spectrum with buses of twelve meters length and more. It now comprised not only the Citaro low-floor urban bus and the rural-service variant Citaro Ü, each twelve meters in length, but the 13 meter long rural-service bus Citaro MÜ as well, the 15 meter long three-axle Citaro L and Citaro LÜ plus the low-floor articulated buses Citaro G and Citaro GÜ, each measuring 18 meters in length. The letter “Ü” always indicates the rural-service variant.
The OC 500 LE urban bus chassis from the Sámano plant in Spain supplements this range. Characteristic of this chassis is the low floor, and a front entrance with no steps which the low floor makes possible. The two-axle, air-sprung chassis takes bodies up to 13.5 meters in length.
In the meantime the Citaro even got a little brother, the Cito. Introduced at the International Commercial Vehicle Show in Hanover in 1998, it surprised the public with a tailor-made midibus concept: alternatively eight, nine or ten meters length and 45 to 65 seats were the key specifications. The Cito had unusual design features: One was a self-supporting aluminum frame with a roof and floor made of aluminum and walls made of plastic. Another was a diesel-electric drive, combined into a compact power pack extending to the roof at the rear of the bus. The Cito impressed people with new solutions and, technically, was far ahead of its time. Perhaps even too far ahead. At any rate, the market responded coolly to the innovative bus. Five years after launching the Cito Mercedes-Benz withdrew it again.
The conventional drive system of the Citaro was more successful. The diesel engines of the Citaro comprised two different series, all six-cylinder in-line engines. The displacement was 6.4 and twelve liters. Outputs ranged from 185 kW (252 hp) and 1100 Nm torque to 260 kW (354 hp) and 1600 Nm. Both engine series are identical in design except for a few adapters. Fuel was injected by the pump-line-nozzle system, which permits high injection pressures and is economical in operation as a result. A fully electronic engine management system further cut consumption. With this technology, the Citaro profited from the development of the Mercedes-Benz Actros heavy-duty truck presented one year earlier, the first vehicle to show such technology.
The diesel engines of the Mercedes-Benz Citaro optionally could be combined with a CRT system (combination of oxidation catalyst and particulate filter). Automatic transmissions from ZF and Voith were available.
Today, diesel engines whose exhaust gases are treated by the SCR (Selective Catalytic Reduction) system are used to comply with the Euro 4 und Euro 5 emission standards. This technology further cuts pollutant emissions substantially, while on the other hand creating prerequisites for possibly reducing fuel consumption still more.
Natural gas engine on request
Optionally, the Citaro also can be had with a natural gas-fired engine which meets the Euro 4 standard. The OM 447 hLAG is available with outputs of 185 kW (252 hp) and 240 kW (326 hp) and with optional EEV certification. This variant even does distinctly better than required by the Euro 5 standard that takes effect in 2008/2009. Together with low noise emissions and the eco-friendly manufacturing methods of the Mannheim factory, this created the prerequisites for awarding the “Blue Angel” symbol for environmentally friendly products to the natural gas-powered buses of Regionalbus GmbH in Mühlhausen, Thuringia.
The Citaro even operates entirely emission-free with the fuel cell drive, in which fuel cells convert the energy contained in hydrogen into electrical energy which in turn drives an electric traction motor. A large-scale test lasting two years was undertaken in ten major European cities with 30 fuel-cell-powered Citaro; another test began in Australia; in China a further practical test followed with three buses. Development of the new drive system, which already was initiated in 1997 with the NEBUS on the basis of the
O 405, thus smoothly continued with the Citaro.
As well as making it possible to install a range of drive systems, the modular design of the Citaro and the tremendous flexibility within the manufacturing process that results from this also provide the ideal basis for producing all manner of special versions. Articulated Citaro GÜ buses are being operated by Regiobus GmbH in Mittweida, Saxony as “road trains”. 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. At night, an ingenious illumination system trans-forms the ceiling into a canopy of stars. In Poland, a Citaro is traveling around from town to town as a mobile energy advice center, while both Hamburg and Munich have Citaro vehicles on standby as large-capacity rescue vehicles for treating the injured following a major incident. Meanwhile, the 101 Citaro models which were given an unmistakable interior and exterior makeover by design specialist James Irvine and then put into service for the World Expo in Hanover in 2000 still turn heads in the city with their special Üstra styling.
The Mercedes-Benz Bus and Coach unit even will customize the Citaro for any customer. It doesn’t have to be an independent body with completely individualized interior appointments. In addition to special technical equipment, customization services include individual advice on interior and exterior design issues from the experts of the design studio in Mannheim. At the studio, the customer and the design consultant jointly plan the paintwork on powerful computers with large 130 x 100 cm monitors.
The interior of the Citaro is even designed step by step on a virtual round through the bus in a realistic 3-D animation. The viewers go through all conceivable seating variants and assess them from all angles. Afterwards the fabrics are selected. Seat layout, seatbacks, side wall paneling, grab rails, the rails of the roof edges, stop request buttons and floor coverings can be combined again and again and optimally color-matched.
Just as up-to-date as the process for choosing colors and fabrics is the production of the Citaro. The bodies-in-white are manufactured in the Bodyshell Center of the Mannheim bus factory and cataphoretically dip-primed there for complete anti-corrosion protection. Group work and a synthesis between technology and manual labor characterize the production process. The entire structure of the bus body-in-white is computer-calculated. The modular design of the Citaro simplifies bodyshell making: A factory in Holysov, Czech Republic, supplies complete floor assembly segments. The bodies-in-white are completed in the assembly bays of Mannheim and the French assembly plant Ligny-en-Barois.
The Citaro entered model year 2005 with a large number of modifications due to the entry into force of the EU directive 2001/85/EC. This directive takes the interests mainly of passengers with restricted mobility into account. The Mercedes-Benz Citaro comes under Class I (urban bus use) und Class II (rural-service use) of the directive. Owing to these regulations, in future the Citaro would have a kneeling function, a revised wheelchair area across from the center door, and a newly designed ramp as standard. Other changes concern external emergency valves and pushbutton switches with a door opening function inside and outside for the double-width center door as well as the number and design of the accommodations for disabled persons and the access to them.
In Germany the Citaro has acquired a clear position of market leadership. At the same it has posted international successes: Of the now more than 17,000 Citaro buses manufactured, around half were exported – a remarkable figure for a market which up until then was nationally dominated in many cases. Among the countries receiving delivery, France ranks ahead of Spain, Italy, Switzerland and the United Kingdom. Major orders included 450 solo and articulated buses for Istanbul, 300 solo buses for Rom and 167 solo and articulated buses for Berlin. The Citaro travels the streets of many great cities of Europe, but not only there: eight units even operate on the French island of La Reunion in the Indian Ocean.
2006 was a year of renewal also for the Citaro. The Citaro K as a compact and especially maneuverable variant with a length of 10.5 meters complemented the range. The Citaro also got a new face. The features included an arched insert suggesting a radiator grille between the headlamps as well as turned turn signal housings with clear glass covers. And the three-dimensionality of the rear end of the Citaro was given stronger emphasis. The V-shaped rear window extends up into the roof. The engine compartment flap ends in a vent at the top. Including the new tail lights, the design idiom is a superb match for the design of the group’s new touring coaches and rural-service buses.
The important technical modifications to the Citaro in 2006 – it also operates as a hybrid bus (Citaro G BlueTec Hybrid) since 2007 – were: independent front wheel suspension and an improved air suspension system. Additionally, an optional electronic roll and pitch control is available for the articulated variants.
New start for the touring coach: the Travego
But now back to the 1990s, when the stage was being set for a new touring coach too. Some important decisions were decided by external factors. The new emission standard Euro 3, new linear measures appreciably beyond the classic twelve meters, 2.55 meters width instead of 2.50 – in the late 1990s there was a flurry of amendments to laws which forced the bus manufacturers to take action. Wolfgang Presinger, just appointed brand spokesman for the Mercedes-Benz Bus and Coach unit then: “We then finally made up our minds to go for broke, telling ourselves: Euro 3, the new overall lengths and the greater width have given rise to a trend which we want to actively shape. That’s why we’re going for a new vehicle.”
This vehicle was called the Mercedes-Benz Travego and superseded the O 404, which could have been adapted to the aforementioned requirements only at great effort and cost. And that is why, after only eight years and around 4500 units, the O 404 faced its end.
The successor was internally coded the O 580 for development purposes, but in the meantime buses with the star were carrying names: Travego, that contains the idea of travel; the word go stands for dynamism; the letter o at the end of this made-up word fit the model families Integro and Citaro.
On the surface, visual reminders of the predecessor were desirable: The driver’s window on the left and the passenger door on the right lead into a functional strip extending on to the rear along the bottom of the bus, much as in the O 404. But in the Travego the strip incorporated the handles of the luggage compartment doors and the side marker lamps. The friendly looking face with the ribbed radiator grille in the middle also recalled the predecessor, producing intentional identification effects. Chief designer Wolfgang Papke: “The Travego embodies innovation and tradition. And the Mercedes-Benz brand stands for these attributes.” Curved headlamps, the three-dimensionally arched windshield extending well into the roof area, plus the steeply sloped wheel arch over the rear axle: the Mercedes-Benz Travego exuded dynamism.
The lines of the Travego are worth a closer look: The exterior mirrors grow organically out of the tops of the front side windows instead of being attached to the A-pillar at the front. The B-pillar, also referred to as “character line,” sweeps upward to the roof and breaks up the large surfaces. At the same time, the line of the pillar takes up the contour of the air conditioner, which because of this does not seem out of place even though it is mounted in the middle of the roof of the Travego. The edge of the roof is designed as a weather strip; the side windows are flush bonded and fitted so that together with the smooth side wall they conduce to easy cleaning and easy covering with decorative designs. The rear window and engine compartment flap are trapezoidal in shape, like a muscular back.
Initially the Travego lineup consisted of three models: The Travego 15 RH raised-floor bus was twelve meters long, rolled on two axles and was 3.44 meters tall. The Travego 15 RHD high-decker towered to 3.71 meters and also had two axles. The flagship was the three-axle Travego 17 RHD high-decker. It attained a length of 13.85 meters. The flexibility of the concept proved itself in 2003 when another high-decker, the 12.8 meter long Travego 16 RHD, was added to the range.
No matter which Travego the driver steers, the cockpit of the new touring coach is perfectly tailored to him. Ergonomically ideal, the entirely new workplace for the driver has been made semicircular; all controls are within easy reach; the steering wheel is unusually compact in diameter. In the middle of his instrument panel the driver no longer looks at a collection of dials, but at an oval display with a large rev counter and speedometer; in between them is a display on which further indicators can be freely programmed and where warning indicators are shown if required.
Shifting by joystick
Instead of the endlessly long shift lever next to the driver’s seat, which drivers had been used to for decades, a short joystick as shift lever knob now grew out of the right side of the semicircular instrument panel. There’d never been one in a bus before. With the joystick the transmission could be operated by a tap of the hand. Richard Averbeck, Travego project manager and future General Manager Engineering at EvoBus: “We wanted to get away from the big sticks with their long shift travel and high shift forces. Changing gears like in a car was our objective.” And it was achieved. To top it all off, the driver’s area was pleasantly spacious and had many places to put things. The tour guide’s seat was even electrically adjustable.
“The coach must look attractive from the outside. Inside it must exude coziness,” said Travego designer Wolfgang Papke. And so the passenger compartment of the Travego also shone in new splendor. Compared with the predecessor: lower window sills, 2.10 meters headroom, full utilization of the width of 2.55 meters and thus 75 millimeters more interior width than in the O 404 – the Travego made a tremendously airy and spacious impression, unmatched by any other touring coach. Newly designed seats featuring one-button operation, folding tables with integral fold-out cup holder, larger luggage racks, almost sculpted service units over each double seat – the passengers of a Mercedes-Benz Travego noticed from the many details that they were taking a seat in a special touring coach. A part of the story are the three design and equipment lines Function, Fashion and Flair, which can be told apart by different decorative designs, fabrics and details such as inserts in the grab handles of the seats. Though the Travego made do without the extremely complex heating system of its predecessor, passengers still could enjoy cozy warmth, the product of a hot water heater with it convectors, enhanced by so-called axial fans as an optional extra. Given the high standard of the Travego, air conditioning was included anyway.
The control of the complete equipment from drivetrain to air conditioner was handled by FPS, the flexibly programmable control system. Five electronic control circuits took the place of several kilometers of cable and various trouble-prone plug connections. This technology had its premiere in a bus two years earlier in the new Mercedes-Benz Citaro urban regular-service.
The driver felt all warm inside not only because of the separate temperature control for his workplace, but also because of the engines. The days of the V-engines in touring coaches were almost over; the designers now banked again on in-line six cylinders. Depending on the model they are installed either horizontally or vertically. The twelve liter in-line six cylinder engine OM 457 with fully electronic control system, four-valve-per-cylinder technology and pump-line-nozzle injection developed 260 kW (354 hp), 300 kW (408 hp) or 310 kW (422 hp). If the buyer set store by more power or the special flair of a V8, he could purchase the Travego with the OM 502 LA. This engine was good for 300 kW (408 hp), 320 kW (435 hp) or even 350 kW (476 hp). For transmissions, there was a choice of Mercedes-Benz six-speed manual transmissions with control cables and pneumatic assistance or, coming a little later, the
ZF AS-Tronic automated manual transmission.
The running gear reliably transferred the power of the engines to the road. The rear axle was an in-house product, first the cast-iron HO8 axle, later the lighter HO6 formed axle made of sheet steel. Up front, instead of an in-house design a ZF axle with twin control arms was used. Its big advantage: the inner turning angle was 58 degrees, which guaranteed an optimally small turning circle. The three-axle coaches had either a self-steer trailing axle or a third actively steered axle, which ensured extreme maneuverability, for example, for reversing.
Electronically controlled disk brakes on all axles
Disk brakes all around can be found on any new bus from Mercedes-Benz, and now also the Electronic Braking System EBS, seen for the first time on an Actros heavy-duty truck three years prior to the Travego premiere. This brake system stands for rapid response, sensitivity, and even wear patterns on all wheels – high grip can be taken for granted, just as can the sturdy framework with reinforcements stretching across the roof and down the sides, which Mercedes-Benz had introduced two years before the Travego in the then new Citaro. So there’s no question whether the Travego passed the ECE R 66 rollover test: this has long been the standard at Mercedes-Benz.
However, safety is a continuous process and never complete, particularly for
Mercedes-Benz. For instance, the first bus to be seen with the ESP electronic stability program was a Travego, at the Hanover commercial vehicle show in 2000. Within the bounds of what is physically possible, through selective braking intervention ESP prevents vehicle oversteer or understeer and can thus make good driver error and avert the development of dangerous situations. From 2002 on, ESP was optionally available for the Travego; from autumn 2003 it was part of the standard equipment – a premiere for buses, as was the standard-fit Brake Assist beginning in 2002.
At the 2004 Hanover commercial vehicle show, in a very near-series innovation study of the Travego, Mercedes-Benz demonstrated the current state of the art in safety technology along with three more new safety systems: the autonomous intelligent cruise control (ART), the Lane Assistant system and the continuous braking limiter. All three systems currently are fitted in the Travego, whose second generation was presented by the group in 2006.
Improvements in detail
This new Mercedes-Benz Travego utilizes the unchanged foundations of the first generation, but surpasses them on all major points: in safety and comfort for passengers and driver, in looks and equipment, and in the environmental friendliness and economic efficiency of the new Euro 4 engines, the Travego sets the new standard for high-quality touring coaches.
Three high-deck touring coaches in the lineup for Western Europe
The new Mercedes-Benz Travego lineup features three high-deck touring coaches: the Travego (max. 15 seat rows, length of 12.14 m, two axles), Travego M (max. 16 seat rows, length of 12.96 m, three axles) and Travego L (max. 17 seat rows, length of
13.99 m, three axles). The overall height of all three variants is 3.71 m.
While the new Mercedes-Benz Travego has a visual affinity with the preceding model, its lines show a clear evolution and refinement. The new model is elegant and at the same time masculine and progressive in appearance. For example the “face” of the coach below the familiar deep and inviting windscreen is now more sculpted, while the new front panel with air intake presents a three-dimensional appearance, has a curved upper edge and is visually more distinctive. All this, together the Mercedes star proudly displayed on a sculpted plinth, makes the front-end design reminiscent of a
Mercedes-Benz passenger car. The new and larger variable-focus reflector headlamps with clear polycarbonate lenses display a prominent kink, while the turn signals are now integrated in the all-glass housing. The new-look bumper and the stylistic integration of the fog lamps emphasize the dynamism at the heart of the new touring coach.
The side view of the new Travego has also been given new emphasis. Now even more prominent than before, the three-dimensional character line created by the B-pillar grows powerfully out of the vehicle body. At its lower end, it sweeps dynamically around into the front entrance door, where a wedge-shaped element forms a visual link between the front and side of the vehicle. At its upper end, the B-pillar sweeps back elegantly above the first two side windows without impairing the passengers’ view in the slightest, before seamlessly merging into the trim panel of the fluently integrated roof-mounted air conditioning system. Its paneling wraps round the roof edge and blends smoothly into the side wall.
To give passengers in the new Travego’s rearmost row of seats a better view, the rear edges of the rear side windows are now steeper and sturdier-looking, rather than rounded as previously. The new LED side marker lights are designed to last the life of the vehicle, with no bulbs to replace. These enhancements make the new
Mercedes-Benz Travego appear more powerful but also more elegant, as well as ensuring stylistic unity. They also ensure an evolutionary continuation of the design language of the previous model.
New-look rear section
The rear end of the Travego too has been enhanced in several key areas. Particularly noticeable are the rounded, three-dimensional tail lights which wrap round into the sides of the vehicle. Each unit has three integrated, light-colored covers for the indicators and the reversing lights. Here too, the appearance is reminiscent of a Mercedes-Benz passenger car, due to the use of typical Mercedes-Benz design themes. Passive lighting segments link the tail lights with the now flat engine compartment flap whose upper section features a newly designed ventilation grille. As well as looking good, the grille is effective at preventing dirt or rainwater from entering the engine compartment. Moving further upwards, new recesses in the rear wall echo the shape of the ventilation grille, and break up the appearance of the surface.
In the rear window, the enlarged Mercedes star is now more prominent and protrudes upwards into the glass area. The engine compartment flap, rear wall and corners of the bumper are more powerfully curved at the sides. Overall the second-generation Travego has a harmonious appearance, exudes typical Mercedes-Benz dynamism and is easily recognizable.
Like its predecessor, the new Travego high-deck touring coach has a body incorporating tried-and-tested reinforcements stretching across the roof and down the sides, thus creating the basis for maximum strength and safety. Design modifications have been made on the left-hand side where the Travego (15 RHD) and Travego M
(16 RHD) models now have two instead of three luggage compartment doors to make the driver’s life easier. The Travego L (17 RHD) now has three such doors instead of four.
Although the wheelbase length remains unchanged, the front end of the new Travego has been extended by 140 mm to provide extra space for the driver and the tour guide as well as a wider entrance for the passengers. At the same time, the developers were able to increase the angle of approach so as to ensure improved handling and maneuverability. And despite the slight increase in overall length and the measures implemented to ensure compliance with the Euro 4 emissions standard, the new Travego weighs less than its predecessor. In the three-star maximum seating versions, including on-board toilet but not including the driver and tour guide seats, the passenger seating capacity is 49 (Travego), 53 (Travego M) and 57 (Travego L).
Safety high on the list of priorities
While the Mercedes-Benz Travego has always provided an exemplary level of safety, the new Travego marks another major step forwards. The extensive standard equipment package now includes the continuous braking limiter – a control system which makes life considerably easier for the driver by preventing the vehicle from accelerating over the speed limit when driving downhill. At first the coach is braked automatically by the retarder, then – after a signal has warned the driver to take action – by the service brakes, thus preventing the vehicle from exceeding statutory speed limits on long motorway descents, for example. Furthermore, the cooling power of the engine has been increased to ensure better dissipation of the heat energy generated by braking and, therefore, extremely stable retarder operation during long periods of braking.
The exemplary standard-fitted safety equipment of the Mercedes-Benz Travego also features the familiar fade-resistant braking system incorporating disc brakes all around, the Electronic Braking System (EBS), Brake Assist (BA), acceleration skid control (ASR), the retarder and, perhaps most importantly of all, the Electronic Stability Program (ESP). The standard-fitted Voith retarder can be operated via a five-stage steering column stalk (standard). However, to reduce service brake wear, the “retarder integration” function also allows the retarder to be activated via the foot brake pedal.
Large H7 halogen headlamps with a high light output are also standard. Powerful Litronic gas discharge headlamps, similar to the xenon headlamps used on cars, are available as an option. Other standard features include fog lamps, a highly efficient system of mirrors providing excellent all-round visibility, the high-strength skeleton with reinforcements stretching across the roof and down the sides, and passenger seats with impact surfaces on the backrests. All this is as much an integral part of the new Mercedes-Benz Travego as the comfort and safety-oriented chassis and suspension.
New assistance systems
Available as an option for the new Travego for the first time, the autonomous intelligent cruise control (ART) automatically maintains a preprogrammed safe following distance from vehicles in front. For example, if the coach starts to approach a slower-moving vehicle ahead or if a slower-moving vehicle cuts across in front of the coach, the retarder and service brakes are activated automatically to slow the coach down and reestablish the preset safe following distance. The deceleration is limited to 20 percent of the maximum available braking power. When there is no longer an “obstruction,” the coach is automatically accelerated back up to the speed previously set using the cruise control function. Although the proximity control system is primarily designed to assist drivers in motorway traffic, it is also helpful on other extra-urban roads and, since it is effective from a speed of 15 km/h, in towns.
A further option, the Lane Assistant, is now available for all new Travego models. A camera system monitors the lane markings and detects when there is a danger of the vehicle leaving its lane. If this happens, the relevant side of the driver’s seat starts to vibrate in order to warn the driver.
Further enhanced driver’s workplace
The developers have also enhanced several aspects of the Travego interior. For instance, the front end has been extended by 140 mm to give the driver more space and provide an extended driver’s seat adjustment range. Furthermore, there is now space for a large bag behind the driver’s seat. On the left-hand side, the practical, multi-compartment driver’s locker has been redesigned. And the parking brake lever has been moved to a new, easier-to-reach position. A further plus is the easier-to-use joystick shift lever and the enhanced Servoshift system, which enables the driver to change gear even more smoothly and precisely than before.
The already exemplary, ergonomic design of the instrument panel in the preceding model has been further improved upon in the new Travego. Now a soft coating which is pleasant to the touch covers the surface of the instrument panel while the previous monochrome display in the instrument cluster has been replaced by a new, high-contrast and easy-to-read color display on the instrument cluster. The standard-specification “Flair” design and equipment line includes a wood-trimmed leather steering wheel while the optional “Fashion” design and equipment line features a leather steering wheel with a fine multi-point surface texture.
Both the tour guide’s area and the entrance benefit from an extra 70 mm thanks to the longer front end of the new Travego. Passengers now board the bus via extremely wide, flat steps. Meanwhile, the new-look tour guide’s seat also features an electrically adjustable backrest and seat cushion as an option.
Video system with DVD player and flat-screen monitors
The roof area above the driver and tour guide area has been completely redesigned and restyled to give it an open, inviting look, with enlarged and lockable compartments on the left and right. This new design necessitated the use of flat-screen monitors instead of the previously installed tube-type units for the video system in the new Travego. Optionally, the front monitor is available in electrically retractable version to give the passengers an even better view. Standard equipment also includes a DVD player.
Upon boarding the coach, passengers are immediately met by the “Mercedes-Benz” brand lettering which, like the “Travego” lettering, is to be found inside on the left and right above the driver’s and tour guide’s seats. Since one of the main aims is to make passengers on board the Travego feel at home, generous dimensions have been maintained, with an exterior width of 2.55 m, generous standing height of 2.10 m and, as a result, an airy and spacious feeling. Differences passengers will notice on board the new Travego include the modified service units beneath the air ducts, whose redesign results in a more integrated appearance. The control buttons, now including illuminated inductive switches for the reading lights and service call function, are now logically integrated right next to the reading lights. Each of the adjustable air outlets is controlled by a thumbwheel.
Another new feature is the lighting concept for the Travego passenger compartment, now centered around ceiling-mounted fluorescent tubes running alongside the luggage racks. The tubes have two light settings and are of particular benefit to coach operators as they have an extremely long service life. The discreet ambient lighting, also new, includes offset lighting for anti-glare illumination of the center aisle below seat level. Furthermore, passengers occupying the rearmost seat row in the new Travego enjoy a better view as the side windows no longer feature a rounded rear edge but, instead, extend back as far as the corner pillar.
Stronger air conditioner
In particularly hot regions, passengers on board the Travego will feel the benefit of a more powerful roof-mounted air conditioning system. The most powerful of the systems available now has a maximum cooling capacity of 39 kW. Further new developments include an air conditioning system with a cooling output of 35 kW. Both new systems have eight evaporator fans to ensure a high airflow rate. Customers therefore now have the choice of an air conditioning system with a cooling capacity of 32 kW, 35 kW or 39 kW, depending on the coach model and where it is to be put into service. Features the new model shares with its predecessor include the tried-and-tested hot water convector heater, with the option of axial fans for increased output.
The general upgrading of the Travego also extends to the robust luggage compartment floor covering and the luggage compartment doors which are now lined on the inside. Next to the center door is a spacious multipurpose area which can be accessed from the center entrance area by pulling back a retractable cover and serves either as an additional stowage compartment or as the basis for the optionally available driver’s rest area.
Torque and power increased
To prepare for the imminent introduction of the Euro 4 emissions standard, the engine lineup for the new Mercedes-Benz Travego has been revised and enhanced significantly. As before, the range includes the OM 457 LA six-cylinder in-line engine with a displacement of twelve liters and the V8 powerplant from the OM 502 LA series. However, the previous entry-level engine, the 260 kW (354 hp) version of the
OM 457 LA, has been replaced by the next most powerful version, which offers a significant increase in performance.
The new base engine for the Travego now develops 315 kW (428 hp). Even more important than the increase in rated output is the substantial boost in torque. Instead of 1900 Nm, the six-cylinder powerplant now delivers an impressive peak torque of
2100 Nm. Thanks to this new, powerful base engine, the performance of the Mercedes-Benz Travego more than lives up to the expectations created by its highly dynamic appearance, under all conditions.
The top-of-the-range OM 502 LA V8 engine – with an unchanged displacement of 15.9 liters and output of 350 kW (476 hp) – also has a maximum torque of 2100 Nm. This engine is available as an option for the three-axle Travego M and Travego L.
Servoshift further refined
All of the engines have their air intake on the left above the drive axle, in a zone located well away from where the dirt is swirled up by the rear wheels. This means that the air cleaners have a long service life. In all models, the standard transmission is the Mercedes-Benz GO 210 six-speed manual transmission which, as before, is operated by a joystick mounted on the instrument panel. Thanks to the enhanced Servoshift system, this transmission now ensures even smoother and more precise gear changes than before. Optionally, the Travego can be specified with the ZF AS-Tronic automated manual transmission with 12 forward speeds. Like the outgoing model, the new Travego is fitted with the tried-and-tested Mercedes-Benz HO6 drive axle.
Less complex electronics
The new Mercedes-Benz Travego features an enhanced electronic system that is again based on the successful flexibly programmable control system (FPS). Even though the number of control units has been cut from six to five, in order to reduce the complexity of the system, functionality has been extended.
The Mercedes-Benz Bus and Coach unit decided to use a conventional electronic control unit with fuses and relays for numerous comfort and convenience systems on board the new Travego, including the sunblinds, power windows, audio/video systems and the galley. The priorities were to allow easy repairs throughout Europe and neighboring countries as well as to facilitate retrofits. By way of example, it is now possible to fit a trailer coupling including a socket without having to worry about downloading extra software, as was previously the case. All in all, the combination of flexibly programmable control system and conventional electronic control proves to be an extremely practical solution.