Editing Interstate 45 (section)

===North Freeway (Houston to Conroe)===
[[File:North Freeway SB.JPG|thumb|Southbound on the North Freeway]]
The last alignment of US&nbsp;75 before the North Freeway was built left Downtown to the northwest on Main Street, turning north at Airline Drive, and then northwest along the present alignment of I-45, then known as Stuebner Airline Road, Shepherd Drive, and East Montgomery Road.<ref name=map-1955/> The freeway replacement was authorized in stages between May 1945 and June 1952, when the [[Texas Transportation Commission]] adopted plans for a freeway all the way between Houston and Dallas. The North Freeway name was adopted in 1956; an unsuccessful proposal in 1965 would have renamed it the Dallas Freeway.<ref name=HF1>{{cite book |last = Slotboom |first = Erik |title = Houston Freeways: A Historical and Visual Journey |year = 2003 |publisher = Oscar F. "Erik" Slotboom |isbn = 0-9741605-3-9 |url = http://www.houstonfreeways.com/ |chapter = Chapter 1: Building the System |access-date = September 11, 2006 |archive-url = https://web.archive.org/web/20060906040202/http://www.houstonfreeways.com/ |archive-date = September 6, 2006 |url-status = live }}{{sps|date=April 2020}}</ref> The first short piece of the freeway to open crossed [[Buffalo Bayou]], connecting the two [[one-way pair]]s from the north end of the Gulf Freeway with the south end of Houston Avenue. This section was opened on December 12, 1955, and allowed US&nbsp;75 to bypass its run on Main Street;<ref name=map-1958/> it included interchanges with [[Allen Parkway]] and [[Memorial Drive (Houston)|Memorial Drive]]. The next piece near downtown opened on July 24, 1962, leaving the 1955 freeway in the Allen Parkway interchange, passing east of Houston Avenue, and connected to an already-built portion at [[Interstate 610 (Texas)|I-610]]. The six-lane Pierce Elevated, which occupies half a block on the southwest side of Pierce Street, required the acquisition of a number of commercial properties; the cost prevented the full block from being used. This portion opened on August 18, 1967, connecting the Gulf and North Freeways and bypassing the "four-street distribution system", which remains in its original form to this day.<ref name=HF4/><ref name=HF3>{{cite book |last = Slotboom |first = Erik |title = Houston Freeways: A Historical and Visual Journey |year = 2003 |publisher = Oscar F. "Erik" Slotboom |isbn = 0-9741605-3-9 |url = http://www.houstonfreeways.com/ |chapter = Chapter 3: Downtown Freeways |access-date = September 11, 2006 |archive-url = https://web.archive.org/web/20060906040202/http://www.houstonfreeways.com/ |archive-date = September 6, 2006 |url-status = live }}{{sps|date=April 2020}}</ref>

The first piece of the North Freeway to be built outside I-610 was an upgrade of existing US&nbsp;75 on Stuebner Airline Road, between Airline and Shepherd drives, opened in December 1959. In April 1961, this was completed to the interchange with I-610, and, on July 24, 1962, the Downtown section was extended north to meet it. As each section opened, US&nbsp;75 was moved to it, temporarily using I-610 to Airline Drive for about a year.<ref>{{cite map |author = General Drafting Company |url = http://www.texasfreeway.com/houston/historic/road_maps/images/1961_houston_enco_highres.jpg |title = Houston, Texas |archive-url = https://web.archive.org/web/20070927072224/http://www.texasfreeway.com/houston/historic/road_maps/images/1961_houston_enco_highres.jpg |archive-date = September 27, 2007 |year  = 1961 |publisher = Humble Oil }}</ref><!--note that I-610 ended at Airline; with the current ramps you can't go from Airline to I-45 north via I-610--> At the other end, US&nbsp;75 was upgraded from [[Spring Creek (San Jacinto River tributary)|Spring Creek]] at the north edge of [[Spring, Texas|Spring]] north to the [[San Jacinto River (Texas)|San Jacinto River]] south of [[Conroe, Texas|Conroe]] in 1960.{{cn|date=October 2024}} In between, the upgrade was completed from [[Farm to Market Road 525|FM&nbsp;525]] to near Richey Road in December 1961, south to the 1959 segment in February 1963, and north to the 1960 segment in March 1963, completing the North Freeway except for the Pierce Elevated (1967). The freeway as initially built had eight lanes (four in each direction) between Downtown and I-610, six to [[Farm to Market Road 1960|FM&nbsp;1960]], and four north of FM&nbsp;1960.<ref name=HF4/>

[[File:2019-07-20 10 25 57 View south along Interstate 45 (North Freeway) from the ramp between westbound Interstate 10 and southbound Interstate 45 in Houston, Harris County, Texas.jpg|thumb|left|Southbound I-45 entering Downtown]]
Like the Gulf Freeway, the North Freeway soon became [[traffic congestion|congested]]. The [[oil boom]] of the 1970s resulted in large-scale [[residential development]] along the highway, most notably [[The Woodlands, Texas|The Woodlands]]. Since the corridor was strongly directional, with 65&nbsp;percent of peak-hour traffic going in the peak direction, a {{convert|9.6|mi|km|adj=on}} [[contraflow lane]] for [[bus]]ses and other [[HOV]]s was implemented later that decade, opening on August 28, 1979, between Downtown and Shepherd Drive (exit&nbsp;56B). The facility, operating during both [[rush-hour]] periods, occupied the leftmost lane of the other direction and was separated from the other lanes with a movable [[Traffic cone|pylon]] every {{convert|40|ft|m}}. In 1980, the existing center [[breakdown lane]]s were restriped for HOV traffic for about {{convert|2|mi|km|spell=in}} from the north end of the contraflow lane. Off-peak traffic, however, was increasing, and construction began in 1983 on a more permanent reversible transitway in the median. Thus, the second transitway in Houston (a month after the one on the [[Katy Freeway]]), opened on November 23, 1984, replacing the contraflow lane.<!--presumably ended at the slip ramp near Shepherd--><ref name=HF4/><ref name=HF6/>

Reconstruction of the mainlanes and frontage roads to handle increased traffic began in 1982 just north of Downtown. No lanes were added south of I-610, but the eight-lane cross-section, with room for a transitway, was continued north as construction progressed. Work was completed south of Airline Drive (exit&nbsp;53) in about 1985, to Shepherd Drive (exit&nbsp;56B) in 1987, and to [[Farm to Market Road 525|FM&nbsp;525]] (exit&nbsp;60A) in 1990; this last opening allowed the transitway to extend to just south of FM&nbsp;525. The [[Hardy Toll Road]], completed on June 28, 1988, between I-610 and I-45 near The Woodlands, added capacity to that part of the corridor, and, in 1990, reconstruction was completed on a short piece of I-45 from the toll road into The Woodlands. Reconstruction continued from FM&nbsp;525, reaching Airtex Boulevard (exit&nbsp;63) in 1997, including part of the [[Sam Houston Tollway]] interchange (completed in 2003) and a transitway extension, Cypresswood Drive (exit&nbsp;68) in 1998, extending the transit way to its present terminus, and the Hardy Toll Road (exit&nbsp;72) in 2003. Work on the section through The Woodlands to Research Forest Drive (exit&nbsp;77) was completed in 2001, including a direct connection to Woodlands Parkway<!--the southbound entrance opened later-->, and, in 2003, work was completed to [[Farm to Market Road 1488|FM&nbsp;1488]] (exit&nbsp;81).<ref name=HF4/> Construction is now complete between FM&nbsp;1488 to the [[Walker County, Texas|Walker County]] line near milepost&nbsp;100 just south of the northbound truck weigh station and [[New Waverly, Texas|New Waverly]], near [[Texas State Highway 75|SH&nbsp;75]] (exit&nbsp;98).<ref>{{cite news |first = Rad |last = Sallee |work = Houston Chronicle |url = http://www.chron.com/disp/story.mpl/metropolitan/moveit/3814116.html |title = Rail on Richmond idea first rejected back in '83 |archive-url = https://web.archive.org/web/20060610224215/http://www.chron.com/disp/story.mpl/metropolitan/moveit/3814116.html |archive-date = June 10, 2006 |date = April 23, 2006 }}</ref>

{{As of|2015}}, widening of the North Freeway from Downtown to the Sam Houston Tollway began. The plan for the project is to widen the freeway by adding managed lanes and adding the North Shepherd on- and offramps also known as [[Texas State Highway Spur 261|Spur&nbsp;261]] (which was already completed) prior to the I-45 widening project. This project has generated major controversy, with proponents claiming it would "enhance safety and mobility", while opponents point out that it would worsen air quality and greenhouse gas emissions, displace hundreds of people, and fail to meaningfully address congestion.<ref name=":1" /> 

Authorities in [[Harris County, Texas|Harris County]] have sued [[TxDOT]] to stop the expansion, and the federal government has investigated the expansion project to determine whether it violates any civil rights or environmental laws.<ref name=":0" /> Among others, the expansion has been opposed by U.S. Representative [[Sheila Jackson Lee]] and Harris County Judge [[Lina Hidalgo]].<ref>{{Cite news|last=Cerota|first=Andy|date=6 December 2021|title=Federal officials now investigating I-45 expansion project|url=https://www.click2houston.com/news/local/2021/12/06/federal-highway-administration-visits-houston-to-address-concerns-over-i-45-expansion-project/|access-date=December 18, 2021|archive-date=December 18, 2021|archive-url=https://web.archive.org/web/20211218182353/https://www.click2houston.com/news/local/2021/12/06/federal-highway-administration-visits-houston-to-address-concerns-over-i-45-expansion-project/|url-status=live}}</ref><ref>{{Cite web|last=Coalition|first=Make I.-45 Better|title=Make It Better|url=https://i-45coalition.org/documents|access-date=2021-12-18|website=Make I-45 Better Coalition|language=en-US|archive-date=December 18, 2021|archive-url=https://web.archive.org/web/20211218182355/https://i-45coalition.org/documents|url-status=live}}</ref> If completed, the highway's width will double to {{Convert|480|ft|m}}, wider than a football field. The highway expansion would displace around a thousand residents, including 919&nbsp;units in 16 apartment complexes, 160 single-family homes, five places of worship, and two schools.<ref name=":2" /> An apartment complex was acquired and vacated by TxDOT, which plans to demolish it for the expansion. TxDOT was heavily criticized for this planned demolition, as the apartment complex slated for demolition had been described as an example of good urban planning. <ref>{{Cite web |last=Jordan |first=Jay R. |date=2022-06-21 |title=TxDOT to tear down apartments for controversial I-45 expansion near downtown Houston |url=https://www.chron.com/news/houston-texas/transportation/article/TxDOT-to-demolish-apartments-to-make-way-for-17255413.php |access-date=2022-06-21 |website=Chron |language=en-US |archive-date=June 21, 2022 |archive-url=https://web.archive.org/web/20220621204935/https://www.chron.com/news/houston-texas/transportation/article/TxDOT-to-demolish-apartments-to-make-way-for-17255413.php |url-status=live }}</ref>

Parts of the freeway are paralleled by the [[METRORail Red Line]].<ref>{{Cite web|title=Houston · Texas|url=https://www.google.com/maps/place/Houston,+TX/@29.7909213,-95.3787253,12.83z/data=!4m5!3m4!1s0x8640b8b4488d8501:0xca0d02def365053b!8m2!3d29.7604267!4d-95.3698028!5m1!1e2|access-date=2021-12-18|website=Houston · Texas|language=en|archive-date=December 18, 2021|archive-url=https://web.archive.org/web/20211218182352/https://www.google.com/maps/place/Houston,+TX/@29.7909213,-95.3787253,12.83z/data=!4m5!3m4!1s0x8640b8b4488d8501:0xca0d02def365053b!8m2!3d29.7604267!4d-95.3698028!5m1!1e2|url-status=live}}</ref>