There are a lot of safety personnel in larger London construction sites as well. I&#x27;ve seen men basically acting as barriers while their mate does work above a footpath.<p>Also there are always people directing traffic in and out of a site, washing down every truck that leaves so there is no mud on the road, etc.<p>I would assume it is more a case of construction in a large city is more difficult logistically as there are stricter standards for noise, mess and pollution.<p>It was always my assumption that these type of jobs were on a rota. It would be pretty bad to make someone work the &quot;human barrier&#x2F;traffic light&quot; job 52 weeks a year.