Washington State Route 523
State Route 523 (SR 523, named 145th Street) is a short Washington state highway located on the city limits of Seattle, Shoreline, and Lake Forest Park in King County.[1] The highway travels 0.20 miles (0.32 km) east to interchange with Interstate 5 (I-5), where the northbound ramps are accessed through nearby 5th Avenue Northeast.[1][5] After the I-5 interchange, the road forms the northern boundary of the Jackson Park Golf Course and later continues to SR 522 at the northern Seattle, southern Shoreline and western Lake Forest Park city limits.[4][6] The SR 523 / I-5 interchange was used by an estimated 28,000 motorists daily based on annual average daily traffic (AADT) data collected by the Washington State Department of Transportation.[8] The Washington State Legislature first established a state-maintained highway on a section of present-day SR 523 in 1937, with the establishment of Secondary State Highway 1J (SSH 1J), which ran from Downtown Seattle to Primary State Highway 1 (PSH 1) in North Seattle, via the current 0.05-mile (0.08 km) long section of SR 523 from I-5 to 5th Avenue Northeast.