``Mumbai has had five flyovers in the last 50 years, it will now have 50 in the next five years,'' announces MSRDC managing director R C Sinha. The Maharashtra State Road Development Corporation was set up by the Public Works Department (PWD) last year to work out the brasstacks of Operation Flyover, the construction of 50 flyovers. It has also been tasked with other prized projects like the Mumbai-Pune expressway and the 25-km-long Sewree-Nhava bridge, the trans-harbour link.

Work on this Rs 1,300 crore project has been spurred by the report of the V M Jog committee submitted to the state government last year, which indicated that flyovers were the only solution. Doomsday predictions estimate a 400 per cent increase in vehicle population, pollution levels and a virtual breakdown in the city's road transportsystem by 2011 AD.

So what role do flyovers fulfil in the island city's concrete clutter? Well, for starters, they're the tearful wish of every motorist or commuter who has spent an hour negotiating the notorious Sion junction during the monsoon. Or for that matter, any other log-jammed junction in the metropolis.

``The flyovers will speed up traffic, eliminate signals and virtually double existing road capacity,'' sums up Sinha. There are 14 major signals between the city and Borivli, with an average waiting time of five minutes per signal. Built at all these main signals, the flyovers will whiz the city's buses, cars and bikes up and over the signals. ``On an average, there will be a saving of an hour on the eastern, western and Sion-Panvel highways,'' Sinha says.

According to the MSRDC, the average speed of a vehicle at Mahim junction in 1962 was 36 kmph, but it has dropped to 13 kmph today. Completion of all the flyovers could see an increase in the average vehicle speed to 24 kmph.

Then there'sthe fuel saving. No idling engines at signals means fuel economy, which has been estimated at Rs 80 crore for all the traffic using the flyovers. This also leads to a drop in pollution, since idling vehicles at signals leads to a dangerous concentration of engine exhaust.

Faster traffic also leads to increased capacity of existing roads, since the capacity of a road is relative to the speed of the vehicles on it.

And the city's traffic police, which has to contend with an additional burden of over 200 new vehicles being added to the city's roads each day, is eagerly awaiting the commissioning of these flyovers. ``Doing away with signals means the flow of traffic till the Dahisar check naka will be continuous,'' says a senior official of the traffic department's planning cell.

Construction has already begun on 21 flyovers and is hurtling towards completion, even as the remaining are being speedily cleared. Aiding this silent revolution is a renaissance in construction techniques, time-saving measures andefficient planning, which has seen plans being approved in just three days.

The drill has replaced the hammer. Sophisticated hydraulic boring machines have replaced archaic pile drivers. ``We can now drive a pile in eight hours using the hydraulic pile drivers, as against the earlier eight days,'' says Sinha. Since the new piles go deeper to the bedrock, there's also an eight per cent saving in concrete.

And finally, to avoid cluttering up work sites, no in-situ or on site fabrication of concrete is allowed. All the concrete blocks are fabricated at a separate site by contractors and transported to the construction site. These pre-fabricated blocks are placed jigsaw-like on the pillars, thus completing the flyover.

``We can literally assemble the bridges in a day if all the pillars are finished,'' Sinha says. Not surprisingly, most of the flyovers are being completed months ahead of schedule. The first flyover at Goregaon will be ready by November, nearly four months ahead of time. The Mankhurd flyoveris already three months ahead of schedule for a 31st December commissioning. A revolutionary time saving, considering that last year's Everrad Nagar flyover took 29 months to build.

Aiding the effort are added inducements to contractors like a Rs one lakh bonus for every day ahead of schedule. The contractors have to shell out Rs 1.50 lakh for every day the project is delayed. Some of the more difficult projects include the Haji Ali to Wilson college road-over-road (ROR). The project, for which foreign consultants have been hired, involves building an additional 2.8 km road over the present congested stretch. The second involves construction of a 1.9 km ROR from JJ Hospital and Bhendi Bazar up to Crawford market.(Sandeep Unnithan is a senior reporter with The Indian Express)