Several examples illustrate the effectiveness of PPPs: - London Underground: The modernization of the London Underground was achieved through a PPP, which resulted in significant improvements in infrastructure and service quality. - Australia's Sydney Harbour Tunnel: This project was delivered through a BOT model, where a private consortium designed, financed, and operated the tunnel before transferring it to the government. - India's National Highways: India's highway network has seen substantial improvements through PPPs, with private companies playing a crucial role in construction and maintenance.