Conceptually, concurrency occurs when local governments provide adequate public infrastructure at the same time as development occurs. Policies to promote concurrency are generally intended to encourage land use patterns that can be served efficiently by public infrastructure, to provide appropriate infrastructure at the time of new development, and to prevent new development from degrading locally agreed-upon service standards for the current users of existing infrastructure. In Washington, concurrency is both a state planning goal and a state-mandated local regulation under the Growth Management Act (GMA).
The GMA Concurrency Goal. Under the GMA, concurrency is one of 14 goals local governments must consider in land use planning. The concurrency goal is intended to ensure public facilities and services (such as sewer, water, roads, parks, and schools) are adequate to serve new development at the time of occupancy without decreasing service levels below locally established minimum standards [RCW 36.70A.020(12)]. The Western Washington Growth Management Hearings Board has determined that the concurrency goal does not apply to state highways [04-2-0038c, WWGMHB].
The Transportation Concurrency Requirement. The GMA also defines a specific transportation concurrency requirement. First, local governments must set level of service standards, or minimum benchmarks of performance, for transportation facilities and services. Once the level of service standard is established, the local government must adopt an ordinance to deny proposed developments if they cause the level of service on a locally-owned transportation facility to decline below the adopted standard, unless transportation improvements or strategies to accommodate the impacts of development are made concurrent with development [RCW 36.70A.070(6)(b)]. "Concurrent with development" means improvements or strategies are in place at the time of development, or a financial commitment has been made to complete them within six years. Local governments may accommodate development impacts by changing the phasing or timing of new development, improving transportation facilities or services to serve the new development, reducing the level of service standard, or revising their land use policies.
Concurrency and State-owned Highways and Ferry Routes. Highways of Statewide Significance are statutorily exempt from the concurrency requirement, except in Island and San Juan counties [RCW 36.70A.070(6)(a)(iii)(C)]. Approximately half of the state highway system is designated of statewide significance. The Legislature did not specifically address concurrency for state-owned transportation facilities that are not of statewide significance.
Following are links to more information about concurrency and the state transportation system.