Sacramento Regional Transit, and featured a low floor design, intended to make loading wheelchairs easier on the driver and the passengers. In 2006–2007, Unitrans added eight new Orion Mark V 40-foot buses (4171-4178) to its fleet, returning to the high-floor design. This decision was made due to lower prices, fleet standardization, and availability of buses. On May 12, 2008, construction began on the new Unitrans Silo Terminal. The terminal was completed in late September 2008. A dedication ceremony took place on October 30, 2008, and was attended by several local dignitaries. October 30, 2008 also marked the 50 millionth rider of the transit system. Unitrans received six new low-floor buses from New Flyer at the beginning of Summer 2009, and received 12 more in 2010. These new buses will replace most of the aging Orion V buses, due to the upcoming end of their fuel cylinder lifespans. Unitrans received delivery of two Alexander Dennis Enviro500 40' double-deck buses in March 2010. In 2019, Unitrans started the transition to battery electric buses. Six New Flyer Xcelsior CHARGE buses were purchased, supported by Federal Transit Administration grants. Unitrans plans to fully transition away from CNG buses to battery electric buses by 2023. The first six New Flyer Xcelsior CHARGE buses will go into service in Fall 2022. Future Unitrans has moved towards an almost-entirely alternative fuel fleet. With the exception of the vintage double-deck buses and two rarely used support vans, the fleet is powered entirely by compressed natural gas. All diesel single-deck buses have been retired from service and have been sold. The Unitrans fleet is currently powered by nearly 95% alternative fuel. Unitrans received delivery in March 2010 of two Alexander Dennis Enviro500 buses, in an attempt to accommodate the high passenger loads while reducing the demand on drivers. These buses are powered by clean diesel engines, which produce the same levels of emissions as the compressed natural gas, which powers the modern fleet. These two buses are not intended to replace the antique double-deck buses, but to complement them and accommodate the high passenger loads that Unitrans experiences on a daily basis. Unitrans has added six New Flyer C40LFR low-floor buses to the fleet, and had 12 more delivered in 2010. The aging 1996 Orion V 35' fleet was retired, as well as four of the remaining 40' Orion V buses. Unitrans purchased three New Flyer Xcelsior low-floor buses