The images below are of the recently tarred service lane at Oshodi, work here was completed barely 6 months ago.
So, apart from the obvious poor quality of work done, why & how exactly did the Potholes occur?
A thread ~
The article points more at snow as being the moisture enabling culprit but we obviously don't have snow in these parts.
2. Constant heating up and cooling of the surface (which causes contractions in the asphalt).
The presence of water above & below the surface accelerates the damage.
When the water is above the road surface it aids the wearing out of the asphalt & loosening up of the stone aggregates that are a part of the asphalt layer.
So, basically water above the surface works its way below after having created cracks in the surface.
This water may have seeped in from above via cracks on the surface or have risen from below from burst water pipes or a seasonal rise in the water table.
Heating & cooling cause a surface to expand & contract in turn.
Ordinarily, this is factored into the design of the road and is one reason asphalt is preferred.
However, asphalt is not infinitely elastic;
Once water is inordinately present in volumes beyond projected levels, wear from above or soft soil below will cause it to yield.
Tyres running over a spot already weakened by water either from soft soil substrate below or loose stones above further aids to defeat the asphalt layer
This fatigue results in cumulative damage which in time widens and deepens the pothole.
This is usually done during construction & accounts for the bulk of work done.
Suffice to say that the road we 'see' is not the actual road per se.
Unfortunately, in Nigeria there are hardly drains on the side of most roads.
Where drains occur, they are usually blocked with plastic bags and bottles which impede the flow of water.
When roads are commissioned, the cost of constructing drains is sometimes near to or as much as the cost of the road proper.
Guess which one your average Nigerian politician would rather spend money on?
Ironically, the absence of drains mean that the lifespan of the road is drastically reduced.
More ironically & even macabre is that this serves the average politician's purpose quite well (more bloated contracts to award)
It does not address the proliferation of Potholes across Lagos and other towns or cities in Nigeria beyond the fact that an inordinately high incidence of Potholes implies in large extent to shoddy work.
The instances observed relate more with the incapacity of the 'contractor' to perform to the required standard.