The Prime Minister Minister Dr. Manmohan Singh has called for building multi-model transport systems in cities that efficiently integrate different modes of public transport. Laying the foundation for the Kochi Metro rail at a function organised at the Marine drive today, he said, an efficient public transport system is critical to ensure orderly growth and development of cities. He said , unless services keep pace with urbanisation the country will face serious problems of growth in urban slums .This may laos lead to crumbling of city infrastructure.