Transportation Development Tax / TDT

The Transportation Development Tax (TDT) is imposed on new development and redevelopment within Washington County. The tax is charged to developers to help pay for the impact new development has on the transportation system. 


The TDT is collected before building permits are issued. In cases where building permits are not required, it is collected before final approval of a development application. However, there are options for payment including:

  • Payment over time
  • Deferral of payment until occupancy, in certain cases

Additionally, credit toward TDT may be approved for construction of eligible road or sidewalk improvements.