and Blue/Silver buses will be used on limited stop routes. These buses will have either Local or MetroExtra on the top of each side of the bus for easy identification. WMATA is adding a total of 533 hybrid buses to replace its diesel bus fleet. Each new "New Flyer Xcelsior XDE40" bus costs $571,737 and is expected to break down less frequently as well as offer greater fuel economy. With the latest purchase of 152 hybrid buses for $89.3 million from New Flyer of America, WMATA's Metrobus fleet will consist of 297 diesel buses, 800 hybrid buses and 458 natural gas fueled buses. Additionally, WMATA placed an order for 110 new buses from New Flyer on September 18, 2019. According to a Sierra Club report, in 2020 WMATA received $4.1 million in funding from the Federal Transit Administration for the purchase of electric buses and charging infrastructure. The report estimated that 50% electrification would reduce the WMATA fleet's greenhouse gas (GHG) emissions by more than 58,000 tons of carbon dioxide (CO2) per year. Divisions There are 9 divisions (a.k.a. depots) in the Metrobus system. Closed depots Routes Numbering Most Metrobus routes follow the rules below: Metrobus routes in Washington, D.C. have either a two digit number (31, 42, 64, etc.) or a letter followed by a number (A2, S2, X8, etc.) Metrobus routes in Montgomery County, MD have a letter followed by a number (C4, Q4, Z6, etc.) Metrobus routes in Prince George's County, MD have a letter followed by two numbers (F12, J12, P12, etc.) Metrobus routes in Northern Virginia have one or two numbers followed by a letter (1A, 16C, 29N, etc.) Odd-numbered routes are typically part-time variants of even-numbered routes. Richmond Highway Express Richmond Highway Express, a.k.a. "REX", is a Limited-Stop bus line that operates between King Street–Old Town station and Fort Belvoir along the Richmond Highway corridor in Fairfax County, Virginia. All REX runs take place on board on any local bus from Cinder Bed Division. REX began service on September 26, 2004, replacing parts of the now-former route 9A (which operated between and stations until it was eliminated on June 26, 2016). The original REX bus fleet consisted of 12 now-retired 2000 Orion 06.501 (VI) buses wrapped (but not painted) in the blue-and-gold color scheme (2073–2084) before the aforementioned Orion 07.501 CNG buses arrived in 2006. The second REX fleet consisted of 12 now-retired 2006