Road Research Laboratory
1933 The Road Experimental Station at Harmondsworth near London was transferred from the Ministry of Transport to the Department of Scientific and Industrial Research. Early research was mainly on road materials and design, with some work on safety.
1939 work on kerbstones and flagstones and testing of road stones was taken over from the National Physical Laboratory
By 1939 the increase in road accidents was causing concern but moves to establish a road safety research board were postponed due to the outbreak of WWII.
WWII: most of the Laboratory's resources were diverted initially to the engineering problems of civil defence and later to work for the Admiralty, Ministry of Aircraft Production, Ministry of Supply, Air Ministry and other government departments. Other activities included input into the design of the Dambuster bomb.
1943 work on road tar was taken over from the Chemical Research Laboratory.
1945 Research into road traffic and safety was added to the work of RRL.
Post-WWII: research steadily expanded to meet the problems created by the rapid growth of road traffic; advances were made in pavements and earthworks. Road and vehicle safety research studied pedestrian accidents, leading to the development of the Zebra crossing in the late 1940s. Other topics included traffic capacity, traffic control, road signs, geometric design, and traffic and transport planning.
The Laboratory was divided into a Materials and Construction Division at Harmondsworth and a Traffic and Safety Division at Langley. A third branch was developed to deal with road and road transport problems in overseas territories, leading to the appointment of a colonial liaison officer in 1950.
1949 RRL's Scottish branch was opened at Thorntonhall
1955 at the request of the Colonial Office, a Colonial Road Research Section was set up, subsequently renamed the Tropical Section,
Investigations into braking performance, lighting systems, direction indicators, safety helmets and street lighting.
1960 the "Priority Rule" at roundabouts was introduced thanks to work undertaken by RRL.
1965 responsibility for road research was returned to the Ministry of Transport; the laboratory was brought under the ministry's control, and the board and its committees were dissolved and replaced by an advisory Road Research Council.
1967 The Laboratory's new facilities in Crowthorne were formally opened.
1970 Transferred to the Department of the Environment. The scope of the laboratory's work was broadened to cover transport systems and transport generally
1972 Name changed to Transport and Road Research Laboratory (TRRL), reflecting the wider remit including freight, traffic and environmental studies.
1976 When a separate Department of Transport was created, the laboratory became a common service of the two departments until 1984 when it became solely part of the Department of Transport.
1992 the laboratory became an executive agency of the Department of Transport
1993 renamed the Transport Research Laboratory.