A department of transportation (DOT) is responsible for maintaining a safe and efficient transportation system. It maintains highway systems, roads, and bridges. It creates regulations to maintain roadways in the United States. At the federal level, it also helps manages time zones and Daylight Savings Time in the United States. By regulating and maintaining roadways, a department of transportation improves the quality of life for travelers.
These departments also remove snow from major roadways by plowing and applying ice melt. The department of transportation is responsible for providing grants for local departments to improve roads, bridges and other infrastructure. The department is also responsible for coordinating with the other main transportation agencies like the Federal Aviation Administration (FAA), National Highway Traffic Safety Administration (NHTSA), and Federal Railroad Administration (FRA).