Washington State Route 539

The Guide Meridian was preceded by a plank road that was built by the Whatcom County government in stages between 1884 and 1885 and fully graded in 1890.[17][18] By November 1891, it stretched 12 miles (19 km) and cost an estimated $6,000 per mile to construct.[19][20] It was destroyed several times by forest fires, including a major fire in 1897 that required using 80,000 board feet of lumber to replace the burned sections.[21]

The Guide Meridian was later reconstructed as a gravel road from Bellingham to the Canadian border in the early 1910s and maintained by a local citizen named John C. Anderson, who received praise from local newspapers for the quality of the road.[22] The section of the Guide Meridian within Bellingham city limits, named Meridian Street, was paved by the city government in 1914.[23] The following year, the county government began a $68,800 improvement program, which included a new bridge over the Nooksack River near Lynden and 5 miles (8.0 km) of pavement between Bellingham and Laurel.[24] The paved Guide Meridian was opened on September 14, 1915, ahead of the Northwest Washington Fair, and the new Nooksack River bridge was completed the following month.[25] The new bridge measured 383 feet 3 inches (116.81 m) in length, the longest of any steel bridge in the Pacific Northwest at the time.[26]

The planked approaches to the Nooksack River bridge were deemed too narrow for automobile traffic and widened by 8 feet (2.4 m) in 1919.[27] Further paving projects on sections of the Guide Meridian were contracted by the county government between 1920 and 1932,[28][29] completing a paved highway from Bellingham to the Canadian border.[30][31] The British Columbia government announced plans in 1931 to link the improved Guide Meridian to the Fraser Highway via a new paved highway.[32]

The Guide Meridian was added to the state highway system in 1937 as Secondary State Highway 1B (SSH 1B), connecting the Canadian border with Primary State Highway 1 (PSH 1), also signed as U.S. Route 99 (US 99) in Bellingham.[33][34] Several bills in the 1930s proposed elevating the Guide Meridian to a primary state highway, but they were not advanced by the state legislature.[35][36] In 1951, the Nooksack River bridge near Lynden was disassembled and moved 30 miles (48 km) upstream to Mosquito Lake Road as part of a widening project on the Guide Meridian.[37]

In 1952, the American Association of State Highway Officials approved the creation of US 99 Alternate, which would run concurrent to SSH 1B from Bellingham to the Canadian border.[38][39] The designation came shortly before the completion of the Aldergrove highway (signed as British Columbia Highway 13).[40][41]

After the completion of the Bellingham Freeway (part of I-5) in December 1960,[42] SSH 1B was truncated to a new interchange at the north end of Meridian Street.[43] During the 1964 state highway renumbering, SSH 1B was replaced by US 99 Alternate and PSH 1 was provisionally renumbered to US 99 before being replaced outright by I-5.[44] US 99 and its alternate routes were decommissioned in 1969,[45] leaving SR 539 to replace SSH 1B when the new state highway system was codified by the state legislature in 1970.[46][47]

SR 539 crosses the Nooksack River on a pair of truss bridges; the southbound (left) span was constructed in 2009.

The state government began planning a major expansion of SR 539 to a four-lane highway in the late 1980s to accommodate local population growth and increased cross-border freight traffic.[48][49] The corridor had been studied for widening in 1970 due to a high rate of fatalities compared to other rural highways in the state, but the projected traffic volumes did not justify expansion at the time.[50] In 1979, the state government funded a $1.4 million project to widen the southernmost section of SR 539 to four lanes with a turn lane between I-5 and Kellogg Road.[51]

The highway was later identified as among the state's most dangerous, with 714 collisions and nine deaths from 1988 to 1993 and 314 collisions and three deaths from 1999 to 2003.[52][53] The first major phase of the project, covering 4.62 miles (7.44 km) between Horton Road in Bellingham to Ten Mile Road near Laurel, was approved for design work in 1999.[48]

Construction of the first phase was originally planned to begin in 2003, but funding issues and negotiations with property owners for expanded right-of-way slowed progress.[49][48] The project began construction in June 2007 after it was allocated additional funding from the state legislature's transportation package.[54][55] The widened, four-lane roadway with center turn lanes was completed in November 2008, including new traffic signals at three intersections, several detention ponds, and two bridge replacements, at a total cost of $66.3 million.[56][57]

The second phase, covering 6.54 miles (10.53 km) of SR 539 between Ten Mile Road and Badger Road (SR 546) in Lynden at a cost of $89.2 million, was included in the 2003 Nickel Funding Package passed by the state legislature.[58] It was originally scheduled to be completed in 2013, but a supplemental legislative package approved in 2004 advanced $60.4 million in funding for the project so it would be completed in time for the 2010 Winter Olympics to be held in nearby Vancouver.[59] While several alternative options were considered for the SR 539 corridor, including carpool lanes and improving parallel roads, WSDOT chose to largely re-use the four-lane roadway configuration with turn lanes already planned for the first phase.[60] The section would, however, include five roundabouts at existing intersections to improve safety and prevent long backups at signals near Lynden.[53][61]

The project was later scaled back to remove the roundabout at Badger Road and the widened roadway beyond southern Lynden due to a projected increase in land and construction costs.[62][63] Construction of the second phase began in March 2008 under a $54 million contract awarded by WSDOT that included a new bridge over the Nooksack River and widening of four other bridges.[64][65] The new Nooksack River span, a 300-foot (91 m) steel truss bridge carrying two lanes of southbound traffic, began construction in April 2009. To avoid placing piers in the river, each half of the bridge was built from the shore and joined together in September.[66][67] It was the first truss bridge to be built in Washington state since the completion of a span over the Snake River on U.S. Route 12 east of Pasco in 1986.[66] The bridge opened to traffic on February 9, 2010, days before the opening ceremonies of the 2010 Winter Olympics.[68]

The first roundabout on SR 539, located at Ten Mile Road, began construction in March 2009 and opened on May 16, 2009, after several delays due to rainy weather.[69][70] A second roundabout was opened at Pole Road (SR 544) on August 17, ahead of the Northwest Washington Fair, and was followed by a third at Wiser Lake Road in October.[71][72] The final roundabout was opened on December 7 at River Road on the north side of the Nooksack River bridge.[73] Construction on the second phase was completed in July 2010 with the installation of cable median barriers to prevent head-on and crossover collisions.[5][74] Since the installation of roundabouts and cable median barriers, collisions on SR 539 have increased but injuries have declined from 96 between 2000 and 2010 to 23 between 2010 and 2018.[61] Plans to widen the remainder of the highway to the Canadian border were adopted by the county government in 2013, but remain unfunded.[2][75]