Urban planning is a powerful tool that can be harnessed to meet an area's economic, social, cultural and environmental needs and to make visions for that area a reality. A host of factors contributes to the successful development and implementation of urban plans, including strong institutional coordination, rule of law, integration across scales and sectors, and financing. But a crucial step in developing strong plans is for cities to gain a deep understanding of their existing and future needs. Technological and social innovations have made this step easier for planners, who can now collect and analyze Big Data to gain better insight into interrelated urban systems. Reliable, accessible data can provide an objective source of information on which to base planning decisions and can strengthen the overall planning process.