"Design a comprehensive transportation infrastructure plan for a bustling metropolitan area with a rapidly growing population. Consider factors such as traffic congestion, environmental sustainability, accessibility for diverse communities, and future scalability. Incorporate advanced technologies, such as smart traffic management systems and autonomous vehicles, while ensuring seamless integration with existing infrastructure. Address challenges related to funding, public acceptance, and regulatory approvals, aiming to create a transformative transportation network that enhances connectivity, promotes economic growth, and improves overall quality of life for residents."