How strange, and to think that the DfT document on Guston says "...the time required for each HGV check (excluding physical examination) is expected to be two to four hours however some may take longer" as well.
They really ought to listen to:
Mr Elphicke (2017) - "With customs, the gold standard is the ten seconds it takes for processing in Singapore"
https://www.conservativehome.com/platform/2017/10/charlie-elphicke-ensuring-we-are-ready-on-day-one-for-any-brexit-scenario-is-the-smart-thing-to-do.html;
Mr Sunak (2017) - "...French customs authorities boasted in 2014, their average time taken to check goods was four minutes seven seconds, hardly a deal breaker for British exporters"
https://www.conservativehome.com/platform/2017/01/rishi-sunak-why-britain-must-leave-the-customs-union.html;
Mr Lilley (2018) - "...many of the problems ascribed to leaving the EU’s Customs Union are imaginary and most of the rest are exaggerated. References to “customs paperwork” having to be “checked at the border” after Brexit conjure up visions of lorry drivers filling in forms which are then laboriously checked against their loads, causing delays and queues. In fact, virtually all customs declarations are made electronically ahead of arrival at a port; most consignments are cleared within seconds of arrival..."
https://www.conservativehome.com/platform/2018/11/peter-lilley-fears-about-leaving-the-customs-union-are-a-mix-of-imaginary-and-exaggerated.html.