 = =   The High Five Interchange , north of downtown in Dallas , Texas , is a massive five @-@ level freeway interchange . It is the junction of two major highways carrying heavy rush hour traffic , the Lyndon B. Johnson Freeway ( Interstate 635 ) and the Central Expressway ( US 75 ) , and is the first five @-@ level stack interchange to be built in the city .   It replaces the antiquated three @-@ level , modified cloverleaf interchange built in the 1960s that caused a severe bottleneck by narrowing US 75 down to two lanes at the junction of the two highways . The looped ramps of the cloverleaf forced motorists to slow down drastically , backing up traffic . Left @-@ hand exits contributed to the congestion . Further , its two frontage roads were not directly connected to each other , making local access difficult .   Alluding to the celebratory gesture , the " High Five " name refers to the five flyover ramps handling the left @-@ turn movements that tower over the landscape . The interchange is as high as a 12 @-@ story building , and includes 43 bridges spread across five levels ( the " High Five " ) , 710 support tiers , and 60 miles of additional highway . The highest ramps are 120 feet ( 37 m ) above ground . The lanes of US 75 , which are on the bottom level , are 20 feet ( 6 m ) below ground level , giving the structure a total height of 140 feet from bottom to top As part of the project , I @-@ 635 was widened to include four dedicated high @-@ occupancy vehicle lanes ( HOV lanes ) that are barrier @-@ separated and reversible .   The roads on the five levels are :   Level I : US 75 , an eight lane highway , four lanes going each way   Level II : The junction of the two six @-@ lane frontage roads , each having three through lanes in each direction , left @-@ turn lanes and turnarounds , and easy access to US 75 and I @-@ 635   Level III : I @-@ 635 , ten regular lanes , five going each way , and four HOV lanes ( two going each way ) separated by barriers   Level IV and V : Direct connection ramps ( two levels ) , eliminating the left exits of the modified cloverleaf   The interchange , with its decorative etchings on precast concrete elements , along with the visually appealing coloration specified by the Texas Department of Transportation ( TxDOT ) , can be regarded as an enormous work of public art . The High Five also incorporates a hiking and bike trail , named the Cottonwood Trail , which runs under all levels of the interchange . The section of the trail passing beneath the interchange was constructed as part of the High Five project by TxDOT .   The interchange is considered by Popular Mechanics as one of " The World 's 18 Strangest Roadways " , calling it a " labyrinth of lanes " and a " five @-@ level marvel of engineering " because of its height , the number of its bridges and other unusual design and construction features .   = = History = =   The High Five Interchange project was planned as a replacement for the existing , antiquated interchange that accommodated 500 @,@ 000 vehicles daily and was located in one of the most intensely developed commercial zones in Dallas . It was a collaborative project between the TxDOT , affected motorists and property owners , and the primary contractor , Zachry Construction . An essential consideration was to complete the project with as little disruption to the traffic flow as possible .   Reasons for upgrading the interchange , in addition to the need to increase traffic flow and reduce congestion , were to improve air quality , safety , and local access .   Zachry Construction Corporation submitted the lowest bid and was awarded the $ 261 million contract by TxDOT , the largest ever by that agency . The construction contract for the High Five Interchange was unique in that it contained elements not found in other construction project contracts . For example , it specified the concrete maturity method to be used to ensure the concrete 's strength ( the first time TxDOT had ever done so ) , and contained an early completion bonus , a sliding scale of up to $ 11 million if the company completed the contract within four years . Also built into the construction contract was a provision that Zachry was charged for " lane rentals " by TxDOT for time they closed down traffic lanes — fees based on hourly assessments and the time of day the lane was closed . The fees ranged from $ 50 to a high of $ 110 @,@ 000 for rush hours . In order not to interfere with traffic flow during construction , the new interchange was designed largely as elevated flyover ramps and viaducts so they could be built high over the existing junction lanes ; once traffic was transferred to the new structures the old lanes could simply be closed off and removed . Little of the original interchange
Ġ= Ġ= Ġ Ġ ĠThe ĠHigh ĠFive ĠInter change Ġ, Ġnorth Ġof Ġdowntown Ġin ĠDallas Ġ, ĠTexas Ġ, Ġis Ġa Ġmassive Ġfive Ġ@ - @ Ġlevel Ġfreeway Ġinterchange Ġ. ĠIt Ġis Ġthe Ġjunction Ġof Ġtwo Ġmajor Ġhighways Ġcarrying Ġheavy Ġrush Ġhour Ġtraffic Ġ, Ġthe ĠLyndon ĠB . ĠJohnson ĠFre eway Ġ( ĠInterstate Ġ6 35 Ġ) Ġand Ġthe ĠCentral ĠExpress way Ġ( ĠUS Ġ75 Ġ) Ġ, Ġand Ġis Ġthe Ġfirst Ġfive Ġ@ - @ Ġlevel Ġstack Ġinterchange Ġto Ġbe Ġbuilt Ġin Ġthe Ġcity Ġ. Ġ Ġ ĠIt Ġreplaces Ġthe Ġantiqu ated Ġthree Ġ@ - @ Ġlevel Ġ, Ġmodified Ġcl over leaf Ġinterchange Ġbuilt Ġin Ġthe Ġ1960 s Ġthat Ġcaused Ġa Ġsevere Ġbottleneck Ġby Ġnarrowing ĠUS Ġ75 Ġdown Ġto Ġtwo Ġlanes Ġat Ġthe Ġjunction Ġof Ġthe Ġtwo Ġhighways Ġ. ĠThe Ġloop ed Ġramps Ġof Ġthe Ġcl over leaf Ġforced Ġmotorists Ġto Ġslow Ġdown Ġdrastically Ġ, Ġbacking Ġup Ġtraffic Ġ. ĠLeft Ġ@ - @ Ġhand Ġexits Ġcontributed Ġto Ġthe Ġcongestion Ġ. ĠFurther Ġ, Ġits Ġtwo Ġfront age Ġroads Ġwere Ġnot Ġdirectly Ġconnected Ġto Ġeach Ġother Ġ, Ġmaking Ġlocal Ġaccess Ġdifficult Ġ. Ġ Ġ ĠAll uding Ġto Ġthe Ġcelebr atory Ġgesture Ġ, Ġthe Ġ" ĠHigh ĠFive Ġ" Ġname Ġrefers Ġto Ġthe Ġfive Ġfly over Ġramps Ġhandling Ġthe Ġleft Ġ@ - @ Ġturn Ġmovements Ġthat Ġtower Ġover Ġthe Ġlandscape Ġ. ĠThe Ġinterchange Ġis Ġas Ġhigh Ġas Ġa Ġ12 Ġ@ - @ Ġstory Ġbuilding Ġ, Ġand Ġincludes Ġ43 Ġbridges Ġspread Ġacross Ġfive Ġlevels Ġ( Ġthe Ġ" ĠHigh ĠFive Ġ" Ġ) Ġ, Ġ7 10 Ġsupport Ġtiers Ġ, Ġand Ġ60 Ġmiles Ġof Ġadditional Ġhighway Ġ. ĠThe Ġhighest Ġramps Ġare Ġ120 Ġfeet Ġ( Ġ37 Ġm Ġ) Ġabove Ġground Ġ. ĠThe Ġlanes Ġof ĠUS Ġ75 Ġ, Ġwhich Ġare Ġon Ġthe Ġbottom Ġlevel Ġ, Ġare Ġ20 Ġfeet Ġ( Ġ6 Ġm Ġ) Ġbelow Ġground Ġlevel Ġ, Ġgiving Ġthe Ġstructure Ġa Ġtotal Ġheight Ġof Ġ140 Ġfeet Ġfrom Ġbottom Ġto Ġtop ĠAs Ġpart Ġof Ġthe Ġproject Ġ, ĠI Ġ@ - @ Ġ6 35 Ġwas Ġwidened Ġto Ġinclude Ġfour Ġdedicated Ġhigh Ġ@ - @ Ġoccupancy Ġvehicle Ġlanes Ġ( ĠH OV Ġlanes Ġ) Ġthat Ġare Ġbarrier Ġ@ - @ Ġseparated Ġand Ġreversible Ġ. Ġ Ġ ĠThe Ġroads Ġon Ġthe Ġfive Ġlevels Ġare Ġ: Ġ Ġ ĠLevel ĠI Ġ: ĠUS Ġ75 Ġ, Ġan Ġeight Ġlane Ġhighway Ġ, Ġfour Ġlanes Ġgoing Ġeach Ġway Ġ Ġ ĠLevel ĠII Ġ: ĠThe Ġjunction Ġof Ġthe Ġtwo Ġsix Ġ@ - @ Ġlane Ġfront age Ġroads Ġ, Ġeach Ġhaving Ġthree Ġthrough Ġlanes Ġin Ġeach Ġdirection Ġ, Ġleft Ġ@ - @ Ġturn Ġlanes Ġand Ġturn ar ounds Ġ, Ġand Ġeasy Ġaccess Ġto ĠUS Ġ75 Ġand ĠI Ġ@ - @ Ġ6 35 Ġ Ġ ĠLevel ĠIII Ġ: ĠI Ġ@ - @ Ġ6 35 Ġ, Ġten Ġregular Ġlanes Ġ, Ġfive Ġgoing Ġeach Ġway Ġ, Ġand Ġfour ĠH OV Ġlanes Ġ( Ġtwo Ġgoing Ġeach Ġway Ġ) Ġseparated Ġby Ġbarriers Ġ Ġ ĠLevel ĠIV Ġand ĠV Ġ: ĠDirect Ġconnection Ġramps Ġ( Ġtwo Ġlevels Ġ) Ġ, Ġeliminating Ġthe Ġleft Ġexits Ġof Ġthe Ġmodified Ġcl over leaf Ġ Ġ ĠThe Ġinterchange Ġ, Ġwith Ġits Ġdecorative Ġet ch ings Ġon Ġpre cast Ġconcrete Ġelements Ġ, Ġalong Ġwith Ġthe Ġvisually Ġappealing Ġcolor ation Ġspecified Ġby Ġthe ĠTexas ĠDepartment Ġof ĠTransportation Ġ( ĠT x D OT Ġ) Ġ, Ġcan Ġbe Ġregarded Ġas Ġan Ġenormous Ġwork Ġof Ġpublic Ġart Ġ. ĠThe ĠHigh ĠFive Ġalso Ġincorporates Ġa Ġhiking Ġand Ġbike Ġtrail Ġ, Ġnamed Ġthe ĠCotton wood ĠTrail Ġ, Ġwhich Ġruns Ġunder Ġall Ġlevels Ġof Ġthe Ġinterchange Ġ. ĠThe Ġsection Ġof Ġthe Ġtrail Ġpassing Ġbeneath Ġthe Ġinterchange Ġwas Ġconstructed Ġas Ġpart Ġof Ġthe ĠHigh ĠFive Ġproject Ġby ĠT x D OT Ġ. Ġ Ġ ĠThe Ġinterchange Ġis Ġconsidered Ġby ĠPopular ĠMechanics Ġas Ġone Ġof Ġ" ĠThe ĠWorld Ġ' s Ġ18 ĠStr ang est ĠRoad ways Ġ" Ġ, Ġcalling Ġit Ġa Ġ" Ġlabyrinth Ġof Ġlanes Ġ" Ġand Ġa Ġ" Ġfive Ġ@ - @ Ġlevel Ġmarvel Ġof Ġengineering Ġ" Ġbecause Ġof Ġits Ġheight Ġ, Ġthe Ġnumber Ġof Ġits Ġbridges Ġand Ġother Ġunusual Ġdesign Ġand Ġconstruction Ġfeatures Ġ. Ġ Ġ Ġ= Ġ= ĠHistory Ġ= Ġ= Ġ Ġ ĠThe ĠHigh ĠFive ĠInter change Ġproject Ġwas Ġplanned Ġas Ġa Ġreplacement Ġfor Ġthe Ġexisting Ġ, Ġantiqu ated Ġinterchange Ġthat Ġaccommod ated Ġ500 Ġ@ , @ Ġ000 Ġvehicles Ġdaily Ġand Ġwas Ġlocated Ġin Ġone Ġof Ġthe Ġmost Ġintensely Ġdeveloped Ġcommercial Ġzones Ġin ĠDallas Ġ. ĠIt Ġwas Ġa Ġcollaborative Ġproject Ġbetween Ġthe ĠT x D OT Ġ, Ġaffected Ġmotorists Ġand Ġproperty Ġowners Ġ, Ġand Ġthe Ġprimary Ġcontractor Ġ, ĠZach ry ĠConstruction Ġ. ĠAn Ġessential Ġconsideration Ġwas Ġto Ġcomplete Ġthe Ġproject Ġwith Ġas Ġlittle Ġdisruption Ġto Ġthe Ġtraffic Ġflow Ġas Ġpossible Ġ. Ġ Ġ ĠReasons Ġfor Ġupgrading Ġthe Ġinterchange Ġ, Ġin Ġaddition Ġto Ġthe Ġneed Ġto Ġincrease Ġtraffic Ġflow Ġand Ġreduce Ġcongestion Ġ, Ġwere Ġto Ġimprove Ġair Ġquality Ġ, Ġsafety Ġ, Ġand Ġlocal Ġaccess Ġ. Ġ Ġ ĠZach ry ĠConstruction ĠCorporation Ġsubmitted Ġthe Ġlowest Ġbid Ġand Ġwas Ġawarded Ġthe Ġ$ Ġ261 Ġmillion Ġcontract Ġby ĠT x D OT Ġ, Ġthe Ġlargest Ġever Ġby Ġthat Ġagency Ġ. ĠThe Ġconstruction Ġcontract Ġfor Ġthe ĠHigh ĠFive ĠInter change Ġwas Ġunique Ġin Ġthat Ġit Ġcontained Ġelements Ġnot Ġfound Ġin Ġother Ġconstruction Ġproject Ġcontracts Ġ. ĠFor Ġexample Ġ, Ġit Ġspecified Ġthe Ġconcrete Ġmaturity Ġmethod Ġto Ġbe Ġused Ġto Ġensure Ġthe Ġconcrete Ġ' s Ġstrength Ġ( Ġthe Ġfirst Ġtime ĠT x D OT Ġhad Ġever Ġdone Ġso Ġ) Ġ, Ġand Ġcontained Ġan Ġearly Ġcompletion Ġbonus Ġ, Ġa Ġsliding Ġscale Ġof Ġup Ġto Ġ$ Ġ11 Ġmillion Ġif Ġthe Ġcompany Ġcompleted Ġthe Ġcontract Ġwithin Ġfour Ġyears Ġ. ĠAlso Ġbuilt Ġinto Ġthe Ġconstruction Ġcontract Ġwas Ġa Ġprovision Ġthat ĠZach ry Ġwas Ġcharged Ġfor Ġ" Ġlane Ġrentals Ġ" Ġby ĠT x D OT Ġfor Ġtime Ġthey Ġclosed Ġdown Ġtraffic Ġlanes ĠâĢĶ Ġfees Ġbased Ġon Ġhourly Ġassessments Ġand Ġthe Ġtime Ġof Ġday Ġthe Ġlane Ġwas Ġclosed Ġ. ĠThe Ġfees Ġranged Ġfrom Ġ$ Ġ50 Ġto Ġa Ġhigh Ġof Ġ$ Ġ110 Ġ@ , @ Ġ000 Ġfor Ġrush Ġhours Ġ. ĠIn Ġorder Ġnot Ġto Ġinterfere Ġwith Ġtraffic Ġflow Ġduring Ġconstruction Ġ, Ġthe Ġnew Ġinterchange Ġwas Ġdesigned Ġlargely Ġas Ġelevated Ġfly over Ġramps Ġand Ġvi ad uct s Ġso Ġthey Ġcould Ġbe Ġbuilt Ġhigh Ġover Ġthe Ġexisting Ġjunction Ġlanes Ġ; Ġonce Ġtraffic Ġwas Ġtransferred Ġto Ġthe Ġnew Ġstructures Ġthe Ġold Ġlanes Ġcould Ġsimply Ġbe Ġclosed Ġoff Ġand Ġremoved Ġ. ĠLittle Ġof Ġthe Ġoriginal Ġinterchange