Much has been said about the Shared Prosperity through Accelerated Improvement to our Road Network (SPARK) programme, which carries a $45-billion price tag. Prime Minister Andrew Holness has been emphatic in making the point that this project is not about patching roads, but about rehabilitation through reconstruction, which can be interpreted to mean correcting structural and geometric defects, before paving the surface. This is a most welcome approach because, if executed according to plan, we are likely to see value for money.

By now, most would agree that the greatest threat to the stability, sustainability and resilience of our road surfaces is not so much the vehicles that traverse them, but water. If during heavy downpours water is allowed to flow along roadways for any extended period of time, over long distances, the speed of the water will accelerate, while growing in force and as such will cause scouring, if not full displacement of the road surface, its base and sub-base. To avoid this from happening, the flow of water must first be controlled, intercepted, and quickly separated from the road surface.

What this is telling us is that, although it is important, while building roads to ensure that the standards and practices which will yield a robust outcome must be observed, it is ultimately the drainage system that is going to determine the longevity of the road. It means, therefore, that prioritising the study and recognition of the existing drainage infrastructure, is paramount. Hence, culverts, box drains, earth drains, and any other form in which these exist, being very important parts of our road network that must be targeted and located. They should be cleaned and/or repaired, and even widened, to accommodate increased volumes of water brought about by additional rainfall, influenced by the undeniable presence and impact of climate change.

Only after the drainage systems have been brought up to standard, with the capacity to accommodate current surface water run-off, should the expectation of longer lasting finished road surfaces be expected.

To avoid the perils now being experienced — because of undue attention to drainage requirements — road surfaces must be suitably graded so as to prevent ponding within the carriageway. Water being allowed to settle on the roadway makes for the first source of destruction of the road surface, because not only is water destructive to the road surface while in motion, but at these instances of ponding, it also undermines the integrity of the road surface, which begins to break and causes the development of potholes. How often have we seen water ponding only metres away from a drain? This suggests that due care was not taken in grading the road surface towards the drain inlets. Also, at those sections of the carriageway, not in close proximity to a drain inlet, it is the standard practice to shape the surface of the carriageway in such a way that the water will almost immediately run off the asphalted surface.

This can be achieved by implementing what is called camber along the straight sections of the roadway and superelevation along curves. By definition, camber is the result of creating the road surface in such a way that the surface slopes downwards away from the centre (crown) of the carriageway, towards the edges, where there may be concrete kerbs and channels, or earth drains to receive the water and transport it to a drain inlet. This intentional tilt acts like a drainage system, channelling rainwater away from the road surface and towards the shoulders. The centre of the road surface in this situation must be the highest point of the surface, which is why it is referred to as a crown. Superelevation is the tilting of the road surface towards one side of the road where the road alignment includes a curve. It is primarily intended to assist drivers to keep their vehicles from sliding off the road when negotiating curves, by counteracting a lateral force acting on the vehicle, with a tendency to push the vehicle off the road and is a major road safety feature. A secondary function of the superelevation is to cause storm water to run off quickly to one side of the road, where it can be collected by and disposed of by a drainage system.

If the SPARK programme fails to adhere to these important principles we will only be sending hard-earned resources ‘down the drain’. It is hoped that there will be resistance to neglecting these basic requirements of road construction, in preference for meeting datelines. Let’s us not sacrifice the durability, sustainability and resilience of rehabilitated roadways on the altar of expedience. If the very first of these roadways is repaired as recommended, it will be a model for all to see and to expect for the other roads. To do otherwise will only serve to further erode the already low confidence that the people of Jamaica have in Government and its roadwork contractors in managing the country’s road network. So the emphasis in delivering the finished product should have built-in the timeline, execution of the aforementioned prerequisites, and not sacrifice quality for volume of output, otherwise we will only succeed in short-changing ourselves.

Glendon G Newsome, PhD, is an associate professor at the University of Technology, Jamaica.