TRF is classed as a non-profit distributing organisation (NPDO), a form of business structure where all profits are reinvested in services or business growth, rather than being distributed to shareholders. TRL's profits are invested in its own research programmes, selected by the TRF to enhance knowledge in critical areas such as safety, environmental impact and sustainable development. See also Vehicle Certification Agency Type approval United Kingdom driving test Zebra crossing MIRA Ltd. SHARP (helmet ratings) Slough experiment References External links https://TRL.co.uk — TRL Limited official website TRL Software — official outlet of TRL Limited Transport-Links.org — contains many developing country RRL/TRRL/TRL documents, manuals, for free download 1933 establishments in the United Kingdom Government agencies established in 1933 Transport research organizations Transport in the United Kingdom Engineering research institutes Laboratories in the United Kingdom Privatised executive agencies of the United Kingdom government Research institutes in Berkshire Wokingham Companies based in Berkshire Private companies limited by guarantee of the United Kingdom