Resurfacing

My personal puzzle for today has me foxed.
Last week the road where my house is was "resurfaced".
Not like my definition of the word "resurfaced", you understand, but something else entirely.
There are quite a few dents, bulges and potholes reappearing since last year when they did exactly the same thing.
The work:
Basically, a small gang of guys in yellow high-visibility gear and safety helmets wanders around with spades, sprinkling little piles of powdered tarmac grit over the blemishes.
WHAT IS THAT?

Now, I'm no pessimist, but I wasn't surprised when this disappeared again over the following few weeks after they were here last year.
When the sun glinted on it, you could see the bald road surface gleaming brightly where the new loose grit had sandpapered off what was left of the previous resurfacing job, several years before that.
At least that was level, though.
This year's effort was left in little mountains and spade-action swathes and looked something like a Jackson Pollack in monochrome.

This time the grit quickly collected into settling points, mostly along the gutter, and helped on its way there by drivers ignoring the temporary speed limit triangles [20mph] and skiing along at well over the legal 30 limit, sending high-speed pieces of gravelly shrapnel over gardens, into glass window panes and pedestrians' eyes. [I'm exaggerating now, but it doesn't feel safe out there =D]
Of course, a lot of this stuff is collecting in the roadside drains which were emptied and cleared only last month.

I'm sure there's a perfectly good reason for this, but it seems a horrible waste of tax-payers' money and I'm certain we didn't vote for it.
Imagine my surprise when, today, the thunderous drone of a road sweeper threatened in the distance, gradually gaining decibels as it approached.

With the infra-sound vibrating my house and my lungs I watched, incredulous, as it sucked up most of the loose grit from the gutters and roadsides.
Never mind my wonder at how the hell all that stone dust, with the weight of it, would FIT into that machine [especially with a panic-induced fuel shortage hitting us already, a week before this alleged tanker-drivers' strike is supposed to begin; Tuesday, the 3rd of April, I was told, which is tomorrow], I'm at a massive loss as to what special new idea some fresh little genius in the Department of Transport [whatever it's called now] has come up with.
I looked at the road in the wake of the gobbling road sweeper and saw that, sure enough, most of the grit which was applied with reckless abandon last week has gone.

Really. Am I missing something?

But perhaps my questions have been answered already.
A short while later a new rumbling hit the air outside.
I looked out again and discovered that little gaggle of surfacers are back [still with their high-visibility gear on] with their spades, but one of them has a bucket.
In this bucket is a hellish-looking black liquid - probably bitumen - which he is pouring over small areas of more severe damage on our road. The others are, more carefully, spreading that same grey grit dust over these patches.
It a least looks a bit more stable than the job they did last week, but as soon as the hot weather comes [I can hope ;) ] it will be slid off again and redistributed by our vehicle wheels.
One year, in the centre of Swaffham, where they had done a job very similar to this on a heavy-use road, the layer of black "glue" was a lot thicker.
It was hilarious for a while, seeing traffic, including heavy goods vehicles, stopped for the traffic lights and other junctions, creeping along extremely slowly with melted tarmac peeling off the road onto their wheels like pastry around a rolling pin. =D
The road was a complete mess.
Pedestrians were getting stuck in it like ants in honey.
Hilarious, that was, until you got indoors somewhere and discovered that your car, and your shoes, were coated in the stuff.
Only petrol would clean it off, out of my own car, of course, but not until after A LOT of transfer, haha.
It made me understand how Midas must have felt, except I didn't get any gold =D.

So why did they put the dust down, then sweep it up?
Was it some sort of obscure "preparation" technique to "sandpaper" the surface a bit flatter?
Was it a very expensive April Fool joke?
I rather suspect it was a huge mistake by someone trying to cut corners and save budgets.
The latter is the most likely explanation as my local council have got previous for those.
The error-maker won't lose his/her job, though.
Our local government seems to be a tad "family"-oriented. Once you're "in", you're there for life.

Oh, I've just heard that road sweeper again.
What fun!
It's on its way back =D