% of ultra-low emission Buses (ULEB) operating in York (Electric and Hybrid) - (low emission Buses before 2022/23)
There are set definitions for Low Emission Buses (LEB), Ultra-Low Emission Buses (ULEB), and Zero Emission Buses (ZEB):
• LEB: Low Emission Buses had to produce at least 15% less greenhouse gas emissions (GHG) than a conventional Euro V diesel bus and meet Euro VI engine regulations. [https://www.zemo.org.uk/work-with-us/buses-coaches/low-emission-buses/low-emission-bus-certs.htm]
• ULEB: To qualify as an ultra-low emission bus, buses must produce at least 30% less GHG emissions than a conventional Euro VI bus and meet Euro VI engine regulations. [https://www.zemo.org.uk/work-with-us/buses-coaches/low-emission-buses/ultra-low-emission-bus-scheme.htm#ULEB]
• ZEB: The UK government’s Zero Emission Bus Regional Areas (ZEBRA) scheme defines a zero-emission bus as a bus: that is zero emission at the tailpipe, with an Ultra Low Emission Bus Certificate or a Zero Emission Bus certificate. [https://www.gov.uk/government/publications/zero-emission-buses-local-authority-toolkit/zero-emission-buses-local-authority-toolkit]