The Transport Engineering Lab of the Indian Institute of Science (IISc.), which studied the cause of repeated accidents on Yeshwantpur flyover, has concluded that design flaw was causing heavy vehicles to be thrown off the flyover, especially when visibility was low.
“This is owing to the poor design of the horizontal curvature. The horizontal curve is very sharp (almost 90 degrees turn), which makes heavy vehicles vulnerable to accidents. Also, lack of super elevation and a vertical curve along with the sharp horizontal curve makes it even more complicated for drivers to safely manoeuvre on the flyover,” the study said.
The study said with increase in speed of the vehicles on the flyover, the centrifugal force acting on the vehicles increases by many folds, throwing the vehicle off the flyover.
The study, conducted by Ashish Verma, Associate Professor, Transportation Systems Engineering, and others at the department, has recommended a slew of measures to make the stretch safer.
The report suggests that height restriction barriers of 2-m height be placed on either end of the flyover to prevent heavy vehicles from taking it.
The report said: “The Yeshwantpur flyover is designed for slow-moving vehicles and for highly dense traffic”. However, as buses also take the flyover, this, if implemented, will force them to take the underpass which may be impractical, the report says.
The report has recommended putting up proper signage on the flyover indicating a hairpin bend, a road turn arrow signage, and a signage along the flyover and on the road at both ends indicating 30 kmph speed limit apart from installing rumble strips to slow down vehicles.
The report has also recommended installing crash barrier along the flyover to prevent vehicles from falling off. “Crash barriers can be put on the sharp turn so as to restrict a speed vehicle and prevent them from tilting,” the report said.
The traffic police have already installed metallic reflectors on the retention wall of the flyover to guide vehicles of the steep turn and had also recommended crash barriers of 1-ft height.
