The following is taken from Wikipedia- Construction Barrel: Construction barrels (officially known as “drums” in the United States) are traffic control devices used to channel motor vehicle traffic through construction sites or to warn motorists of construction activity near the roadway. They are used primarily in the United States, but are occasionally used in Canada, Mexico and Costa Rica.
Until the late 1980s, construction crews typically used 55-gallon steel drums to guide traffic through construction areas. They were painted orange and white and filled with sand or water to keep them in place. Because the drums were steel and weighed down with sand or water, extensive damage would occur to vehicles striking them. Plastic barrels that are commonly seen on American roadways today began emerging in the late 1970s and 1980s; steel 55-gallon drums were largely phased out by the 1990s and may no longer be used as traffic control devices in the US.