What was wrong with the bus — and the bridge

In the aftermath of the accident on Gemini flyover, the safety of Metropolitan Transport Corporation buses and the sturdiness of flyovers have come to light. Though experts claim that the flyovers are safe, there is ambiguity when it comes to the safety of MTC’s vehicles.

K. Natarajan, general secretary of MTC Employees Progressive Union feels they are unsafe. “There is no space for maintenance of buses. In a place which can accommodate 2,400 buses, 3,500 buses are parked. There is also shortage of maintenance staff and spare parts,” he said.

On Wednesday morning, Prasad, the driver of the bus on route 17 M began his shift around 6 a.m. After a couple of trips, he was asked to change the bus as it had some faults. He set off on his afternoon trip in the replacement bus that met with the accident on Gemini flyover. The driver’s seat in the second bus was a little shaky, Mr. Natarajan said.

Experts say that the new buses are better than the old ones. “The braking system is better. But the bus body is pathetic. It can crumble if the vehicle meets with an accident,” said an expert.

Flyovers seem to be in a better state. Even though Highways Department engineers reiterated that the Anna Flyover was structurally in good shape and adequate for urban conditions, a few traffic planning experts expressed concern about the “tight turning radius”, especially for long buses. When the flyover was designed, the buses were of relatively lesser length and the flyover was adequate for such vehicles. Today, the State has some of the lengthiest buses, with extra overhang. Hence, engineers stressed the need for caution on the part of drivers.

“The turning radius varies with speed. For a vehicle with a speed of 25 km per hour, a 15-metre turning radius is enough. The geometric design is not likely to be the cause of the accident. Speeding and the resultant centrifugal force could have been the reason,” said K.P. Subramanian, former professor of urban engineering at Anna University.

Highways Department officials however said the bearings and expansion joints of the bridge are in good shape and the design is perfect. Officials pointed to the fact that there had been no accidents on that stretch so far. Even though some of the bridges constructed after Gemini flyover have deteriorated, the latter continues to be in good shape.