Primary State Highways were major state highways in the U.S. state of Washington used in the early 20th century. They were created as the first organized road numbering system in the state in stages between 1905 and 1937 and used until the 1964 state highway renumbering. These highways had named branch routes as well as secondary state highways with lettered suffixes. The system of primary and secondary state highways were replaced by sign routes (now state routes) to consolidate and create a more organized and systematic method of numbering the highways within the state.
History
The first state road, running across the Cascade Range roughly where State Route 20 now crosses it, was designated by the legislature in 1893 (However, this road wasn't actually opened until 1972). Two other roads—a Cascade crossing at present State Route 410 and a branch of the first road to Wenatchee—were added in 1897. The Washington Highway Department was established in 1905, and a set of twelve State Roads, numbered from 1 to 12, were assigned. A thirteenth was added in 1907, and State Roads 14 to 18 in 1909.
However, it was not until 1913 that a connected system was laid out—earlier state roads had been disconnected segments of road needing improvements. The seven primary roads were only assigned names, while the older state roads kept their numbers as secondary roads. In 1923, most state roads were assigned new numbers, though the primary and secondary split remained, and several roads remained named only. The United States Numbered Highways were assigned in late 1926, overlapping some of the State Roads.
The first major reworking of the system was passed in 1937, including a complete renumbering. A number of Primary State Highways were designated, while Secondary State Highways were suffixed spurs off those. For instance, Primary State Highway 1 was the Pacific Highway (present Interstate 5), and Secondary State Highway 1B was a spur from Bellingham to the Canadian border (now State Route 539). U.S. Routes kept dual designations with State Highways. By 1952, the present highway shield, in the shape of George Washington's head, had been adopted.
The primary/secondary state highway systems were replaced by the current numbering system in the 1960s, at the behest of the state legislature following the 1962 World's Fair in Seattle. The signs for the new highway numbers, which would be organized based on their general direction and—for secondary routes—a leading digit, first were posted in late 1963 and took effect in January 1964. The new numbers also coincided with existing U.S. Routes and new Interstate Highways to reduce confusion and eliminate duplicate numbers. The PSH/SSH signs were removed by 1970.
Secondary State Highways
Secondary State Highways (SSH) were branches of Primary State Highways with lettered suffixes used from 1937 to 1964.
Branches of PSH 1
Branches of PSH 2
Branches of PSH 3
Branches of PSH 4
Branches of PSH 5
Branches of PSH 6
Branches of PSH 7
Branches of PSH 8
Branches of PSH 9
Branches of PSH 10
Branches of PSH 11
Branches of PSH 12
Branches of PSH 13
Branches of PSH 14
Branches of PSH 15
Branches of PSH 16
Branches of PSH 17
Branches of PSH 21
Branches of PSH 22
Primary State Highway 1
PSH 1 followed the route of U.S. Route 99 (now Interstate 5) from Vancouver to Blaine. It also served U.S. Route 99 Alternate (now SR 11) in Skagit and Whatcom counties.
Primary State Highway 2
This route followed the route of U.S. Route 10 (now Interstate 90) from Seattle to near Ellensburg, then U.S. Route 97 to Peshastin, then U.S. Route 2 to Spokane, then US 10/I-90 from Spokane to the Idaho state line. A southern branch of PSH 2 followed the route of Washington State Route 18 from Snoqualmie to Tacoma.
Primary State Highway 3
This route followed Interstate 82 from Ellensburg to the Oregon State line (concurrent with U.S. Route 97 from Ellensburg to Union Gap and U.S. Route 410/12 from Union Gap to the Tri-Cities), U.S. Route 410 (now U.S. Route 12) from the Tri-Cities to Clarkston, U.S. Route 195 from Clarkston to Pullman, SR 27 from Pullman to Oaksedale, US 195 from Oakesdale to Spokane, U.S. Route 2 from Spokane to Mead and U.S. Route 395 from Mead to the U.S.-Canada border. Spurs extended along I-82/, SR 125 and SR 129 from Tri-Cities, Walla Walla and Clarkston to the Oregon State Line