The logo for <a href="https://en.wikipedia.org/wiki/United_Kingdom" class="extiw" title="w:United Kingdom">United Kingdom</a>'s <a href="https://en.wikipedia.org/wiki/MOT_Test" class="extiw" title="w:MOT Test">MOT Test</a>, a <a href="https://en.wikipedia.org/wiki/vehicle_inspection" class="extiw" title="w:vehicle inspection">vehicle inspection</a> test. It features the logo for the MOT Test, 'three triangles', representing the original three items tested, brakes, steering and lights.
The Ministry of Transport, now <a href="https://en.wikipedia.org/wiki/Department_for_Transport" class="extiw" title="w:Department for Transport">Department for Transport</a>.
circa - 1960
Own work  using: <a rel="nofollow" class="external text" href="https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/519129/know-your-traffic-signs.pdf">Know Your Signs</a> - page 111