I-182 is defined by the Washington State Legislature as SR 182, part of the Revised Code of Washington as §47.17.020. As a component of the Interstate Highway System, the highway is listed as part of the National Highway System for its entire length, classifying it as important to the national economy, defense, and mobility. The Washington State Department of Transportation (WSDOT) maintains the freeway and designates the corridor as a Highway of Statewide Significance, which includes highways that connect major communities in the state of Washington. WSDOT also conducts an annual series of surveys on its highways in the state to measure traffic volume, which is expressed in terms of annual average daily traffic (AADT), a measure of traffic volume for any average day of the year. WSDOT calculated that the busiest section of I-182 is between its interchange with SR 240 and the Interstate 182 Bridge in Richland, where approximately 60,000 vehicles used the freeway on average each day in 2013; in contrast, the lowest traffic level on I-182 was 8,900 vehicles at its western terminus with I-82.