The departments of Public Works and Transportation merged at the end of 2010 in the interests of efficiency and to eliminate duplication. The separate divisions remain.

The Public Works Division is responsible for maintaining all county buildings as well as almost 160 miles of county-owned roads, including the Bronx River Parkway, 86 bridges and traffic signals. The division also monitors all capital projects for the county government. Additionally, the division offers many "shared" services for local governments, school districts and other districts.

The Transportation Division oversees the operations of the county's Bee-Line Buses and the Westchester County Airport and works with the Office for the Disabled on providing ParaTransit services. Additionally, it runs special programs to encourage commuting into Westchester as well as county-wide.