India's financial capital unveiled its first monorail system yesterday, a much-delayed project that aims to boost the city's creaking transport infrastructure and ease traffic on its notoriously congested roads.

The first phase of the transit system, which opens to the public today, will ferry passengers in green, pink and blue carriages along an 8.8 kilometre stretch in the city's east, with the line expected to extend to about 20 kilometres in length and into south Mumbai next year.

Mumbai is famed for its poor roads, heaving traffic and a claustrophobic local train network, which carries millions to work each day and on which thousands die each year -mostly from illegally crossing the tracks.

The monorail aims to ease congestion for commuters in the busy eastern suburbs and help connect them with the city's trains.

When completed it will have capacity for 100,000 to 200,000 passengers a day.