Since 21 January 2024, 40 Mercedes‑Benz Citaro hybrid city buses have been making an important contribution to increasing environmental sustainability, passenger comfort and service quality in suburban traffic in the Italian city of Rome. Bus company Autoservizi Troiani recently acquired the new hybrid vehicles from the Italian Daimler Buses sales company, Daimler Buses Italia. These hybrid buses were commissioned just 20 days after a contract was signed with the city of Rome (Roma Capitale)following a public tendering process. The contract was promptly implemented, resulting in 15 percent of the local public transport in Rome being transferred to the joint venture of ATI Autoservizi Troiani S.r.l. and SAP S.r.l. for the next eight years.

“This agreement between us and the city of Rome presents a number of ambitious challenges. The ultimate goal is to run all scheduled services with a fleet of electric buses, putting sustainability at the forefront,” says Giovanni Troiani, President of Autoservizi Troiani.

Once a regular service is up and running in the Municipio V suburb of Rome, situated to the east of the Tiber River, the new Citaro hybrid bus fleet is expected to reduce fuel consumption by up to 8.5 percent compared with conventional diesel engine vehicles. Autoservizi Troiani also expects to make savings of up to ten metric tonnes of CO2 per year – roughly equivalent to the absorption capacity of around 2,400 trees in an urban environment.

Stefano Giordani, President and CEO of Daimler Buses Italy, commented on the important partnership with Autoservizi Troiani: "We are very proud that Daimler Buses is contributing to improving the service, comfort and quality of life in the suburbs of Rome thanks to the quality of the Mercedes‑Benz Citaro hybrid. Our production plant in Germany also provided a great deal of support by bringing forward deliveries ahead of schedule so the vehicles could be handed over on time."

The striking appearance of the new low-floor hybrid buses with the Mercedes star can't be missed in urban traffic. The dark red design with the white lettering from Autoservizi Troiani immediately stands out. Each of the 40 three-door Citaro hybrid solo buses with a length of just over 12 metres can transport up to 108 passengers. They have 26 seats and offer standing room for 82 passengers. On-board comfort is guaranteed by the spacious feel and high seating comfort on board these buses. Passengers with limited mobility will be able to board and alight with ease thanks to a manually-operated folding ramp. There is also a wheelchair space in the standing area.

Designed for use in urban areas, the Citaro hybrid mild hybrid city buses combine the advantages of a combustion engine and electric drive. The OM 936 h six-cylinder diesel engine with an output of 220 kW (299 hp) is coupled with a 14 kW electric motor. It is powered by fully "green" energy and supports the combustion engine during phases of high power demand. When braking and decelerating, the electric motor converts this kinetic energy into electricity. It has a separate 48 V supply, which is low-voltage technology, making it safe to use. Supercapacitors with a high power density are used as energy storage units in the compact “Supercaps” hybrid module, which is stowed on the roof at the rear area of the bus, space-saving, and protected in the event of a crash. The mild hybrid drive reduces fuel consumption and pollution emissions, which improves operational efficiency and reduces air pollution in the suburbs of the Italian capital.

Numerous innovative safety and assistance systems prevent front-on collisions, while turning assistance and lane departure warning systems help the driver, ensuring a safe and comfortable journey for the passengers. In addition to Sideguard Assist 2, Citaro hybrid buses are equipped with an Active Preventive Brake Assist system and a tyre pressure monitoring system (TPM). The air conditioning system in the passenger compartment is capable of completely renewing the air volume on board every three minutes. In addition, high-performance particle filters with an antiviral functional layer minimise the risk of infection while on-board.