You can obstruct the highway legally if you have applied for consent, posted Notices etc. The only exception being an emergency.
If you do block the highway you have to put up barriers, warning notices and take due care and minimum the obstruction.
Lunchtime today, walking along Newland from the city centre to the County Council Offices, found four breeze blocks and two strips balanced on top outside Top Nosh a food shop (one of a small parade of shops including a cobblers and Fodders another food shop) obstructing the highway, an excellent trip hazard. No workman in sight, no work being done to the front of Top Nosh, not that would have excused blockage of the highway or the hazard it created.
Anyone blind or partially sighted would have tripped. As indeed someone almost did as I passed by.
Anyone disabled or women with children in a buggy would have been forced out into a hazardous road, a very busy trunk route through the city centre.
I was told it had been like it all morning by someone who had been forced out into the road when they passed by earlier.
As I was passing by the County Council I popped in and asked that action be taken. I spoke to someone in Highways and insisted that as it was on their doorstep and constituted a hazard they got someone out immediately.
Whether anyone did deal with it I do not know as although I asked that they contact me they failed to do so, but when I passed by an hour later after lunch the obstruction had been removed.
What makes this all the worse is that it was only last week the Lincolnshire Echo reported that contractors had been fined £12,000 with £1,000 costs for obstructing the highway and putting passers-by at risk.