By V. N. Prasad, Design Engineer & PMC; Roads (Retd.)
With due respects to my learned friends who staged silent protests against straightening of the stretch between Kalamandira and the Mosque on Hunsur Road near Jaladarshini Guest House, I wish to make the following observations from a design engineer’s perspective. Having practiced Road Engineering from ‘Drawing Board’ stage to ‘Project Management’, my focus is only on rectification of defects rather than merits and demerits of alternatives.
In a recent conversation with SOM Editor-in-Chief K.B. Ganapathy, he observed thus: “Prasad, you are like a pontiff in saffron rendering your discourses through your articles in SOM. Sadly, no one bothers to take your views forward.” Thinking citizens and non-thinkers of the government merely prefer to read the articles but do nothing. Therefore, I confine to ‘case-specific’ points and relevant circumstances. My contentions from the time I first observed this stretch as per road transportation engineering fundamentals were:
- The stretch needs corrections.
- Branches of trees need trimming to enable tall-loaded trucks to pass safely.
- All the trees with dangerous inclination from ground level — towards the road — need to be uprooted as they are vulnerable to crashing during rains.
Decades passed. Accidents occurred. Injuries and deaths were reported. Interestingly, during 2005-2009, the Mysuru-Bantwal Road was undertaken for upgradation by State Highway Department — from two-lane ‘Single Carriageway’ to a four-lane, ‘Dual Carriageway’, and a median in between. It would have been better to rectify the Kalamandira and Mosque stretch during upgradation works. Sadly, that did not happen. I wrote about this too but none amongst either thinking citizens or the government took cognisance of it, much less called me for any discussions. I wish to invite the attention of the readers to the following points to substantiate the need for correction of the stretch, in clear terms.
- Geometric design considerations include design vehicles, design speed, sight distance, horizontal and vertical curves, super elevation, widening, gradient, approaches etc. Art of designing lies in balancing these factors for optimising ‘safe disposal of traffic in quickest possible time.’
- This particular stretch has two serious deficiencies from East to West (Kalamandira to Paduvarahalli). One: Long straight stretch and a sharp curve. Two: Falling gradient along the sharp curvature.
- ‘Long approach, Sharp Curve and Falling Gradient’ are all ingredients of bad design and invitation to accidents. Town Planners’ and Design Engineers those days failed to factor the above.
- A vehicle accelerating on the straight stretch (called ‘Tangent’ in road engineering) beyond a certain velocity is sucked into ‘Centrifugal Force’ and tends to skid away from the road.
- This exactly has been the phenomenon in this case wherein injuries and loss of lives are reported. It is attributable to the failure on the part of implementing agencies — the government — to provide safe design.
- When the volume of traffic is high, vehicle speed is well under control. But designs are based on critical conditions. When traffic volume is low and the speed is high, not only drunken drivers and reckless racers but also normal drivers tend to accelerate on long tangents and lose control when they see a sharp curve suddenly on a down gradient.
- If one were to apply engineering ‘Jurisprudence’ to the causes of accidents, injuries and loss of lives, the government would be in serious trouble. Compensations payable would be heavy.
- Safe disposal of traffic volumes in quickest possible time is the essence of road engineering.
- Road humps and metal barricades not only defeat the above purpose but also are undesirable for the following reasons.
- ONE: Road humps puddle up rainwater. Stagnant water on a bituminous surface encourages seepage. Water in bituminous layers will disintegrate the bitumen layers leaving dangerous potholes adjoining the toe of the hump. There are umpteen such cases all over the city.
- Also, the road surface immediately adjoining the road hump is highly vulnerable to abrasion. This is because of heavy vehicles going into high gears after crossing the humps. This is termed ‘Traction’ due to wheel loads. We may observe this condition at many places in city.
- TWO: Rumblers cause extreme discomfort to all vehicles. You will find them in plenty along the Ring Road. They also hold rainwater in multiple strips that will cause disintegration of bitumen underneath. Couples with young children on their two wheelers are the worst affected. They may trip while going over 8-10 Rumblers.
- ‘Metal barriers’ are the most unscientific and bizarre way of controlling traffic. Our Police scatter the barriers in utterly shocking patterns, bereft of any common sense. Heavy vehicles snaking through these barriers create a torsion effect on the surface of the road that will cause damages.
In conclusion, I contend that it takes decades to set right the wrongs committed by the government. The phenomenon called ‘Trust Deficit’ in civil society is on account of negligence of the government in fundamental aspects of road engineering. Unless the government wakes up doing the right thing the first time, such issues will continue to haunt the tax-payer.