Editing Interstate Bridge (section)

==Second bridge and renovations==
[[File:SWIMMING POOL OF THUNDERBIRD MOTEL ON THE COLUMBIA RIVER WITHIN YARDS OF THE INTERSTATE BRIDGE CONNECTING WASHINGTON... - NARA - 548083.jpg|thumb|left|Interstate Bridge in 1973 as seen from the now demolished Thunderbird Hotel on the Oregon side]]

Plans to address congestion on the first Interstate Bridge, which carried over 30,000 vehicles per day by 1948, were drawn after [[World War II]] by highway officials in Oregon. The chief highway engineer, R. H. Baldock, proposed a second span over the Columbia River after it was determined that expanding the existing bridge was not feasible. Several sites were proposed and surveyed, but ultimately a twinned span west of the original bridge was chosen in September 1950 by Oregon and Washington. The proposed reinstatement of the toll led to a lawsuit that was heard by the [[Washington Supreme Court]] in September 1953 and decided in the states' favor.<ref>{{cite news |last=Seekamp |first=William |date=February 19, 2023 |title=Interstate Bridge: Second span revives tolls |url=https://projects.columbian.com/2023/02/19/interstate-bridge-second-span-revives-tolls/ |work=The Columbian |accessdate=June 26, 2024 |archive-date=June 12, 2024 |archive-url=https://web.archive.org/web/20240612141650/https://projects.columbian.com/2023/02/19/interstate-bridge-second-span-revives-tolls/ |url-status=live }}</ref>

In 1958, a $14.5 million (${{formatnum:{{Inflation|US|14.5|1958|r=1}}}}&nbsp;million in {{Inflation-year|US}} dollars) project created a second, almost identical span and doubled the capacity of the bridge. The new bridge was built with a "humpback" that provides {{convert|72|ft|m|1|abbr=on}} of vertical clearance and minimizes bridge openings.<ref name=wood-2001/> Construction began in summer 1956,<ref name="oreg-1956jul17">{{Cite news |author=<!--Staff writer(s); no by-line.--> |title=Construction of New Interstate Bridge Near Start |newspaper=The Oregonian |date=July 17, 1956 |page=1}}</ref><ref name="oreg-1956sep2">{{Cite news |author=<!--Staff writer(s); no by-line.--> |title=Piers Poured Under Water; Contractors to Try New Method in Construction of Interstate Bridge |newspaper=The Sunday Oregonian |date=September 2, 1956 |page=16}}</ref> and the new, parallel bridge opened to traffic on July 1,&nbsp;1958.<ref name="oreg-1958jul2">{{Cite news |last=Hauser |first=Paul |title=Rites Open {{not a typo|2d}} Bridge Over River |newspaper=The Oregonian |date=July 2, 1958 |page=1}}</ref>

At the time the new bridge was opened, the old one was temporarily closed for rebuilding to give it a matching humpback section. When both bridges were first open concurrently, on January 8,&nbsp;1960,<ref name="oreg-1960jan8">{{cite news|author=<!--Staff writer(s); no by-line.-->|title=Twin Interstate Spans Open to Travel Friday|newspaper=The Oregonian|date=January 8, 1960|page=1}}</ref> each bridge became one-way (the new bridge for southbound traffic and the old one for northbound traffic) and tolls were reinstated at $0.20 for cars, $0.40 for light trucks, and $0.60 for heavy trucks and buses. The tolls were removed in 1966 after the construction expenses were paid off.<ref name = "Wood-Wortman"/><ref>{{Cite news |url=https://www.oregonlive.com/environment/index.ssf/2008/08/i5_bridge_tolls_divide_portlan.html |title=I-5 bridge tolls divide Portland, Vancouver |last=Rivera |first=Dylan |newspaper=The Oregonian |date=August 9, 2008 |access-date=July 13, 2011 |archive-date=June 9, 2011 |archive-url=https://web.archive.org/web/20110609160500/http://www.oregonlive.com/environment/index.ssf/2008/08/i5_bridge_tolls_divide_portlan.html |url-status=dead }}</ref>

A $3 million (${{formatnum:{{Inflation|US|3|1990|r=1}}}}&nbsp;million in {{Inflation-year|US}} dollars) upgrade to the lift cables, [[expansion joint]]s, and a deck repaving was completed in 1990. The [[diesel generator]] used to power the lift was replaced in 1995 at a cost of $150,000. In 1999, the bridge was repainted at a cost of $17&nbsp;million. A $10.8&nbsp;million electrical upgrade was completed in mid-May 2005.<ref>{{cite web |publisher=[[Oregon Department of Transportation]] |title=Interstate Bridges Electrical Upgrade |url=https://www.oregon.gov/ODOT/HWY/REGION1/interstate_bridges_elec/index.shtml |access-date=July 13, 2011}}</ref> The damaged [[trunnion]] on the northbound bridge was replaced in September 1997, requiring a full shutdown of I-5 for six days; the project was completed ahead of the original schedule, which anticipated a 21-day closure.<ref>{{cite news |date=September 22, 1997 |title=It's full speed ahead for I-5 bridge traffic |pages=A1, A11 |work=The Oregonian}}</ref> A temporary [[commuter train]] was operated by [[Amtrak]] from [[Union Station (Portland, Oregon)|Union Station]] in Portland and [[Vancouver station (Washington)|Vancouver station]] during peak hours.<ref>{{cite news |last=Mize |first=Jeffery |date=November 30, 2019 |title=Clark Asks: Why can't Amtrak be used to commute to Portland from Vancouver? |url=https://www.columbian.com/news/2019/nov/30/clark-asks-why-cant-amtrak-be-used-to-commute-to-portland-from-vancouver/ |work=The Columbian |accessdate=January 14, 2024 |archive-date=January 15, 2024 |archive-url=https://web.archive.org/web/20240115064745/https://www.columbian.com/news/2019/nov/30/clark-asks-why-cant-amtrak-be-used-to-commute-to-portland-from-vancouver/ |url-status=live }}</ref> The [[free public transport|free trains]] had ten round trips and drew an average of 1,335 passengers per day; the low ridership was attributed to the isolated location of Vancouver's station.<ref>{{cite news |last=Hamilton |first=Don |date=September 17, 1997 |title=Amtrak commutes take on cruise aura |page=A12 |work=The Oregonian |url=https://www.newspapers.com/article/the-oregonian-amtrak-commutes-take-on-cr/163880820/ |via=Newspapers.com |accessdate=January 24, 2025}}</ref><ref>{{cite news |last=Oliver |first=Gordon |date=September 23, 1997 |title=Closure of I-5 bridge demonstrates transit's value |page=A1 |work=The Oregonian}}</ref> The northbound bridge's trunnion was replaced in 2020 with all traffic carried on the southbound bridge, arranged into two lanes in the peak direction controlled by a [[barrier transfer machine|zipper machine]].<ref>{{cite news |last=Heffernan |first=Jack |date=September 19, 2020 |title=Day 1 of I-5 Bridge trunnion replacement project mostly on track |url=https://www.columbian.com/news/2020/sep/19/day-1-of-i-5-bridge-trunnion-replacement-project-mostly-on-track/ |work=The Columbian |url-access=limited |accessdate=January 14, 2024 |archive-date=January 15, 2024 |archive-url=https://web.archive.org/web/20240115064746/https://www.columbian.com/news/2020/sep/19/day-1-of-i-5-bridge-trunnion-replacement-project-mostly-on-track/ |url-status=live }}</ref>