What do we mean by a trap?

A Trap is a devise that could put somebody in trouble unexpectedly. Further a trap is not a visible thing and usually it is a hidden devise.

We can see a few road geometrical traps on recently constructed roads. These traps also do not indicate any signs until vehicles meet up with accidents in unexpected ways. Unfortunately, these traps are not taken in to account deeply by the road designers involved with designs and contractors during the constructions.

The intention of this article is to draw the attention of road designers and users about such roads. There are a number of catastrophic accidents that has happened closer to newly developed hair pin bends and other critical bends in upcountry recently. This situation is common to national roads and provincial highways. Since road surfaces are mostly smooth and free from pot holes, everybody tends to identify causes for these accidents as drivers faults, mechanical faults or loss of breaks, overloading etc. Then, as usual, the chapter would be closed with these visible justifications.

The specific reason behind these accidents appear to be the poor road geometrical engineering approach. It is understood that all the guidelines that are recommended in the GEOMETRICAL DESIGNS OF ROADS (RDA, 1998) are not adopted as common practice. These guide lines explain (refer chapter 7.4.1) the risk of designing the vertical and horizontal alignment independently. Independent approach would cause unsafe traveling background for vehicles accordingly. Colonial practice for such locations was to keep critical horizontal curves without steep slopes, as option for such complex designs.

Such profile which don’t adopt integrated approach for steep hair pin bends creates Traps on Roads for long vehicles. These traps create sudden internal and latent damages to the vehicle by twisting the main bars of the chassis. Then these hidden damages makes the vehicle unfit and the next moment there would be an accident.

When the road surface level is not within the tolerances of springs, vehicles move with just three tyre points while one tyre point tries to move freely. If the vehicles are loaded, then chassis would take its self-weight as lever arm and twists. The next moment, internal hinges would be formed and it affects the braking system, steering system and suspension system. The mismatch in levels of the road surface would be reflected to the chassis by forming the internal, unexpected destruction. This mismatch is because of the poor design approaches being adopted in general.

Mainly designers might be ignoring the essential clauses of the Standards of Road Design guide lines due to the limitations of land for proper road profile, while improving roads. This situation would be highlighted in rural hilly terrain roads which are about to be implemented under ADB funded projects .Therefore it is required to explore more and carry out academic studies and empirical research on this critical technical issue. The ultimate intention of any positive steps taken would be to contribute to saving lives and prevention of catastrophic road accidents. Several strategies are open to discuss in the road design criteria and traffic control criteria to suit to the the local conditions of the country.