This week, the Chennai Corporation has begun a topology survey of major roads, to help it identify which ones need to be re-designed for the construction of better footpaths.

The roads, all of which are bus routes, include Greams Road, Road, Binny Road, Thiru Vi Ka Road, Valluvarkottam High Road, Sterling Road, Ethiraj Salai, Pantheon Road and Gandhi Irwin Road among others.

Funds have been allocated for the survey, which, in a first of its kind, will use the geographic information system and other technology.

The process includes a study of the roads’ geometric properties, spatial relations and the impact caused by the continual change of shapes and sizes of various structures on roads.

The survey is technology-intensive and is likely to be completed quickly in a few days. All the 71 bus routes, identified a few months ago for development of 48 km of additional footpaths, will be covered in the survey.

The footpaths, officials said, will be designed with granite kerbs and slabs. Efforts are being taken to make them obstruction-free and user-friendly, and also to make them accessible to the disabled.

Their design will be based on data collected about trees, streetlights and existing drains on the roads. The civic body is planning to complete constructing the footpaths in four months and expects them to ease pedestrian movement in heavily-congested areas such as Egmore, the official added.