PennDOT oversees programs and policies affecting highways, urban and rural public transportation, airports, railroads, ports, and waterways. More than three-quarters of PennDOT's annual budget is invested in Pennsylvania's approximately 120,000 miles of state and local highways and 32,000 state and local bridges. PennDOT is directly responsible for nearly 40,000 miles of highway and roughly 25,400 bridges, a system first established in 1911. Roughly 7,100 of PennDOT's complement of nearly 11,463 employees are engaged in the maintenance, restoration, and expansion of the state highway system. They work in central headquarters in Harrisburg and 11 engineering districts, with facilities in all 67 counties. PennDOT also administers the state's 12 million vehicle registrations and 10.1 million driver's licenses and IDs, and oversees safety and emission inspection programs.