as time, weather, advertisements, & service advisories. The screens are supplied by contract from 3 different vendors and are installed on new bus deliveries starting in 2017 while buses built after 2008 are currently receiving retrofits. A new livery was also introduced, replacing the blue stripe livery on a white base that had been in use in one variation or another since the late 1970s. The first of these buses entered service in mid-May 2016 on the Q10 route. Buses operating on clean or alternative fuels also make up a significant portion of the fleet, particularly since the establishment of the MTA's "Clean Fuel Bus" program in June 2000. Buses running compressed natural gas (CNG) were first tested in the early 1990s, and were mass-ordered beginning in 1999. Hybrid-electric buses, operating with a combination of diesel and electric power, were introduced in September 1998 with the Orion VI, and mass-ordered beginning in 2002 with the Orion VII. These hybrid buses proved to be useful, at least the 2006-2007 models, for these models cost significantly less to repair and maintain than earlier units. As of December 2022, the fleet has over 1,100 diesel-electric buses and over 700 buses powered by compressed natural gas, which make up less than half of the total fleet. This is the largest fleet of either kind in the United States. In 2017, the MTA ordered a test fleet of ten forty-foot battery-electric buses, five from New Flyer and five from Proterra, the XE40 Xcelsior CHARGE and Catalyst BE40 models respectively. These were all leases, which expired in 2021. In 2019, the MTA ordered their first battery-electric sixty-foot articulated buses, with an order of fifteen XE60 Xcelsior CHARGE buses from New Flyer, deployed on Manhattan Select Bus Service routes. In April 2021, the agency placed an RFP for forty-five new forty-foot battery-electric buses. Later in 2021, the MTA awarded New Flyer the contract for the electric bus order, set to arrive in late 2022 and 2023. 15 more buses were added to the originally 45 bus contract, making for a total of 60 buses allotted for MTA NYCT. Fixed-route fleet details A roster of the fleet is shown below. Not included below are buses and vans not open to the general public (Access-A-Ride vans, taxicabs, and employee shuttle buses), retired buses, or demonstration buses. This list also does not include buses formerly operated by MTA Long Island