Wikipedia:WikiProject U.S. Roads/Washington/Highways of Statewide Significance

The following are Highways of Statewide Significance or in the National Highway System:

US 2: I-5 to Idaho
SR 3: US 101 to SR 104
SR 4: US 101 to SR 432
- NHS only: SR 432 to I-5
I-5: Oregon to Canada
SR 8: US 12 to US 101
SR 9: SR 522 to SR 530 (HSS only), SR 546 to British Columbia (both)
NHS only SR 11: ferry to I-5
US 12: US 101 to Idaho
SR 14: I-5 to US 97
SR 16: SR 3 to I-5
SR 17: US 395 to Moses Lake Airport (HSS only north of I-90)
SR 18: SR 99 to I-90
SR 19: SR 104 to SR 20 (HSS only)
SR 20: US 101 to US 2 (HSS only east of I-5)
SR 20 Spur: ferry to SR 20
SR 22: I-82 to US 97
SR 26: I-90 to US 195
SR 28: US 2 to SR 281
I-82: I-90 to Oregon
I-90: I-5 to Idaho
NHS only SR 96: park and ride to I-5
US 97: Oregon to Canada (HSS only between SR 22 and I-82)
SR 99: I-5 to proposed SR 509 (HSS only), SR 509 to SR 104 (both)
- NHS only: South 188th Street to airport
US 101: Oregon to SR 401, SR 4 to I-5
SR 104: US 101 to I-5
NHS only SR 109: US 101 to Pacific Beach
SR 125: Oregon to US 12
SR 127: US 12 to SR 26
NHS only SR 128: US 12 to Idaho
NHS only SR 166: SR 16 to naval fuel depot
SR 167: I-5 to I-405
SR 169: SR 164 to I-405 (HSS only)
I-182: I-82 to US 395
US 195: Idaho to I-90
I-205: Oregon to I-5
SR 240: Stevens Drive to US 395 (HSS only east of I-182)
SR 270: US 195 to Idaho
SR 281: I-90 to SR 28
NHS only SR 303: SR 304 to SR 3
SR 304: SR 3 to ferry
SR 305: ferry to SR 3
SR 307: SR 305 to SR 104
SR 310: SR 3 to SR 304
US 395: I-82 to Canada
SR 401: US 101 to SR 4
I-405: I-5 to I-5
SR 432: SR 4 to I-5
SR 433: Oregon to SR 432
NHS only SR 500: I-5 to SR 503
SR 501: I-5 to Port of Vancouver
NHS only SR 502: I-5 to SR 503
NHS only SR 503: SR 500 to SR 502
SR 509: I-705 to 11th Street (HSS only north of Marine View Drive), I-5 (HSS as proposed; NHS via South 188th Street) to SR 99
SR 512: I-5 to SR 167
NHS only SR 513: SR 520 to Northeast 73rd Street
NHS only SR 516: I-5 to SR 167
SR 518: SR 509 to I-5
SR 519: I-90 to ferry
- NHS only to West Seattle Bridge (via Alaskan Way)
SR 520: I-5 to SR 202
SR 522: I-5 to US 2
NHS only SR 524: park and ride to I-5
SR 525: I-5 to SR 20
SR 526: SR 525 to I-5
SR 529: I-5 to Port of Everett
SR 530: I-5 to SR 9 (HSS only)
SR 539: I-5 to Canada
SR 543: I-5 to Canada
SR 546: SR 539 to SR 9
SR 704: I-5 to SR 7 (HSS only)
I-705: I-5 to Schuster Parkway
SR 970: I-90 to US 97

Selected non-state highway NHS routes:

11th Street: I-705 to SR 509
Airport Road: I-5 to SR 526
Airport Way/Logan Avenue/North 6th Street/Park Avenue/Park Drive: SR 167 to I-405
Denny Way: Western Avenue to I-5
Western Avenue/Elliott Avenue/15th Avenue Northwest/Holman Road/Greenwood Avenue/Westminster Way: SR 99 to SR 99
East Marginal Way: I-5 (via Boeing Access Road) to SR 99
West Marginal Way: SR 509 to West Seattle Bridge
West Seattle Bridge: West Marginal Way to I-5