Flyover design flaws can be corrected

The Delhi Traffic Police had earlier conducted a survey, under which it identified 162 areas prone to waterlogging. Most of these include the mouths of several flyovers and underpasses. Some areas were inundated under two-feet-deep water. “The report was submitted to the civic agencies, but they are yet to act on it,” said Muktesh Chander, Special Commissioner of Police (Traffic).

During and after the downpour between Monday and Friday, commuters had a harrowing experience wading through waterlogged mouths of flyovers at Palam, Dwarka, Punjabi Bagh, Dhaula Kuan, Moti Bagh and <g data-gr-id="45">Karkari</g> More and underpasses at Moolchand, Sarita Vihar and Dwarka.

“This problem cannot be avoided if the <g data-gr-id="50">rain fall</g> received is higher than the rate of discharge of water. A major role in connection to this are played by the level of foresightedness in the design finalised for flyovers and underpasses and the resources used for the construction,” said PK Sarkar, HoD of transport planning at the School of Planning and Architecture.

He added when the design of a flyover is proposed, it is to be ensured that the gradient should accommodate the ‘rainwater run-off’. Secondly, in India, flyover designs are still drafted on two-dimensional planes – dealing with the cross-sections and L-sections. However, most of the developed countries have evolved to three-dimensional designing.

For instance, Win/Road is a popular designing programme used worldwide for the purpose. It originated in Japan. “Programmes like that can even produce virtual rain, helping designers foresee the rainwater run-off pattern and set the gradients accordingly,” he said.

But the flyovers and underpasses in Delhi have already been constructed. What can be done now? <g data-gr-id="36">omething</g> called Surface Correction Profiling is an answer to this, said Sarkar. For Flyovers, this consists of <g data-gr-id="37">re-locating</g> the vacuum points, ensuring that the rainwater run-off flows into gutters. For underpasses, civic agencies can go for motor pumps to relieve the area.