Which federal act is known for its significant transportation funding and was signed into law in 2012?

Answer: A — MAP-21

The federal act known for its significant transportation funding and signed into law in 2012 is the Moving Ahead for Progress in the 21st Century Act, commonly referred to as MAP-21. This legislation aimed to streamline and improve the nation's surface transportation programs. It provided critical funding for various transportation initiatives, including highways, bridges, and transit, while also introducing significant reforms aimed at increasing the efficiency of federal transportation funding. MAP-21 also set in motion policies that focused on improving safety and enhancing infrastructure in a rapidly evolving transportation environment. The other options refer to legislative acts that were either signed into law before 2012 or focus on different aspects of transportation policy. For instance, the FAST Act was later, signed into law in 2015, and also aimed at funding transportation projects. The Safe, Accountable, Flexible, Efficient Transportation Equity Act and the Surface Transportation Assistance Act were earlier measures focused on similar goals but do not align with the 2012 timeline of MAP-21.