Washington State Route 523

State Route 523 (SR 523, or 145th Street) is a state highway in the U.S. state of Washington. The highway's west end is at SR 99 in the cities of Seattle and Shoreline. Its east end is at SR 522 in the cities of Seattle and Lake Forest Park. The highway is long. The highway meets Interstate 5 (I-5) also in Seattle and Shoreline.