During the 1964 highway renumbering, a new state route system replaced the existing primary and secondary state highways and SR 3 was designated along SSH 14A, PSH 14, and PSH 21 on its present route when it was codified in 1970. Construction of the freeway section of SR 3 began in 1963 between SR 304 in Navy Yard City and Silverdale west of Bremerton and was opened in February 1968. The freeway was extended north to Poulsbo in late 1973, and further north to Naval Submarine Base Bangor in 1977 after the arrival of "Ohio"-class submarines at Bangor. WSDOT re-built the interchange between SR 3 and SR 303 in Silverdale at a cost of $26 million, paid for by a 2003 gas tax. The new interchange, opened in November 2007, split the western terminus of SR 303 between two exits, signed as 45A and 45B, and removed a loop ramp that created turning conflicts. WSDOT began study of a Belfair bypass in 1966 and completed a provisional report in 2010 that did not recommend constructing a bypass of the community, instead opting for a project to widen the highway and add safety improvements that began work in fall 2013.