Why does it often appear to passers-by that your workmen are standing around drinking tea, or that the work area appears to be deserted?
A number of the processes involved in National Grid's Streetworks require a certain amount of time in between operations, to allow for concrete to fully harden to ensure the road is reinstated to the required specification for example. Where this is the case, it is practical for the workmen to take a break, or to perhaps do some of the paperwork associated with the job.
In the case of planned works, National Grid has to complete projects within timescales agreed with local authorities - or risk paying penalties for 'overstaying'. So time really is money.