India, Dec. 23 -- After lying dormant in the city's archives for almost half a century, a 120-foot DP Road has finally moved from yellowing pages onto Mumbai's chaotic streets. Ground zero is a 250-metre stretch in Kandivali east, and the battle has been monumental. It involves a booming township, warring politics, disparate land claims, bureaucratic hurdles, a court case - and Singh Estate, a colony of 310 slum families who stand in its way.

For more than a decade, when battle lines were first drawn, the residents of Singh Estate resisted every effort to treat them as casualties of development. Squatting on 250m of land earmarked for the DP Road, they were labelled as slum dwellers but had grown into a colony, with some homes as large a...