Greater Chennai Corporation plans to introduce a rule that contractors must own milling machines and not rent them. This move comes after many complaints were registered that roads were dug up, but not laid immediately, causing road safety issues, according to S.Rajendiran, Chief Engineer (General), GCC.

Acknowledging the complaints, Mr. Rajendiran stated, ‘The tender qualifications for the contractors remain that they must own an asphalt plant and have adequate power paver and road roller close to the site. Milling equipment is rented by the contractors, as the work is seasonal and a one-time affair. As the rent cost is time-bound, they mill multiple roads and lay roads after all lanes under the contract are dug up. Hence there is a delay.’

He mentioned that if the roads are not laid immediately after being dug up, a fine of ₹5,000 or ₹10,000 is levied, based on the repetition of violation, which is often benign to the contractors. ‘A new qualification that mandates contractors to own milling machines will be introduced for the next set of tenders to be floated in the upcoming week. This will ensure that the contractors mill a road and can subsequently lay it. Also, the contractors have been the same over the years for road laying, and this may introduce new players as well,’ he said.

Road height and quality

‘Roads laid three or four years ago are milled and those older — i.e. the layers below the aforementioned — cannot be dug up as it is tough and cost more. Further, milling is done so that the top layer is half a foot lower than the home levels,’ he said.

A soil quality – California Bearing Ratio (CBR) – test is done 500 metres from the existing top layer on the Bus Route Roads (BRR) to assess the strength of the subgrade (the layer beneath the surface) as well as the thickness of the base.

The engineer added: Ideally, the top layer has to be half a foot lower than the homes. Interior roads are laid as per the CBR value and traffic density as well. Now, in the added areas, the sub-base [subgrade] laid by the previous local bodies is usually not of good quality. GCC plans to hold a discussion with the residents of the road and receive a letter from them on road-related concerns. Next, the lowest house in the road will be identified and the top layer height can be determined as well.