You must remember that in the early days there was little or no heavy equipment to help build the roads, it was all manual labour, the pickaxe being the most handy piece of equipment. For larger excavations of course there was the steam driven shovel or excavator, nothing like a tractor backhoe that you see today.
The men in the photograph above you can quite easily spot their ranking on the job. The workmen all wore cloth caps, while all the foreman or foremen wore the badge of a bowler hat. The gentleman in a homburg was most likely a manager from either the local council or from the contractor.
Of course, today, that form of recognition has long since gone, the workmen either ware, yellow or blue hard hats, and the foreman and supervisors wear white safety hats.