William Marques (Letters, LJ, December 2007) is, of course, correct in stating that the first UK installation of columns designed to detach in impact was on the A1 many years ago. Doug Simpson has referred to this in various presentations and, with hindsight, it should have been mentioned in our article {LJ, October 2007). The reality is though that the concept was not taken seriously by the industry or by Highway Authorities at that time, so it never took off.
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