Arizona Historic Bridge Inventory - azdot.gov · somewhat shallower girders, to create greater under-bridge clearance. This Wash Bridge uses this latter design

STATE OF ARIZONA HISTORIC PROPERTY INVENTORY FORM

Wash Bridge

PROPERTY ICENTlMCAllON

county Plma inventory numba 0107.0 milqmt 277.90 inventory rout. I 10; Frontage Rd locatbn 3.8 rnl West Jd SR 83 footwe intwsodod Wash cityhricity V d USGS quadrangle V d district 81 UTM r d w a m 12.524462.3544957

STRUCTURbl. iNFORMATION

main span number 3 main span type 101 appr, span number 0 appr* wan type degree of skew 45 guardrail type 4 main span lsngth 72.0 rupers8&re concrete dab structure length 88.0 rubstruaurs concrete abutments, wingwalls and piers roadway width 24.0 f lowlddng concrete deck with cmphcrlt overlay str&re width 26.7 othor fwtures concrete slotted g u a r d d s

HISTORIM INFORMATION

construaion data 1928 ddgnsrlonglnrsr Arlzona Highway Department project number FAP 90-A builderlmtranor Veuier & DT&, El Paso TX informaUon source ACOT bridge remrda s8Khre owmr Arizona Department of Transportation alteration da*) altwations

NATIONPL REGISTER EVALUATION

For additknal information, aee "Vehkular Brldger in Arizona 188019W

lnventwy score 44 National Regirtw ~ u ~ t i ~ ~ e R o ~ w t y ~acunendkn Form

NRW diglbllity eligible NRWcritwia A x B- C~ signif. stabrnont mu-preserved example of early ASHD standard

bridge design; on major mute

FORM COMRElED BY

Clayton B. Eraser, Prindpal FFiASERdedgn 420 South County Road 23E Loveland, Colorado 80537 31 October 2004

FRASERDESIGN

W A S H BRIDGE Strutve Na 1020

datedphow: FekaUCWU)1)3 wdlvrtlbn: s d muth + n u 03.02240 03.02.241

W A S H B R I D G E

CONSTRUCTlON HISTORY

Early in 1927 Arizona Highway D e m e n t engineers began drafting plans for improvement to U.S. High- way80 southeast of Tucson. Known locally asthe Tucson-Benson Highway, the road was part of the national Ocecm-to-Ocean Highway that extended east-west across southern Arizona. The proposed work wasdesig- nated as Federal Aid Projed 90, and involved grading, road surfadng and construction of droinage structures of some 21 miles of roadway for an aggregate cost of $165,000. BY MW the drawings were com~lete. - - - - One part of the construction involved building a minor concrete bridge over an intermittent wash near Vcdl. As delineated by AHD, the structure was comprised of three concrete slab spuns supported by concrete abutments and piers on spread footings. The 27-foot-wide concrete deck w& bounded on both sides by AHD- standard concrete guardrds with slotted cutouts.

The highway department received bids for FAP 90-A in December 1927 and awarded the construction contract to the Veeter & Dmis Construction Company of El Paso, Texas. The contractors began work early the following year under the supervision of AHDResident Engineer J.R. Van Horn. By September AHD reported the highway as almost complete; within weeks Veeter & Dcrvis had the work finished. Since its completion, this small bridge has carried mcdnline traffic until construction of Interstate 10 in the early 1960s. Since that time, the bridge and adjacent roadway have fundoned as a frontage road to the interstate.

SIGNIFICANCE STATEMENT

This srnall-scale bridge in Pima County is historically noteworthy for its association with US 80. Alternately known as the Ocean-to-Ocean Highway, the road has served historically as the principal east-west trans- continental route across southern Arizona, carrying the heaviest traffic loads in the state. Built in the 1920s during a period of extensive highway construction in Arizona, the WcLsh Bridge was an integral part of this significant highway. The bridge is technologically important as a representative example of AHD bridge construction. The state had begun using concrete for brIdge superstructures as early as 1910. The earliest girder bridges, suchas the Antelope HflBridge [abdl in YumaCounty and the ScmtaCruz River Bridge [El661 in Santa Cruz County, employedtwo deep girders that were cast integrally with the concretedeck. By 1922, cdter a brief dalliance with a three-girder design, AHD had refined its girder standard to incorporate four somewhat shallower girders, to create greater under-bridge clearance. This Wash Bridge uses this latter design. It is today distingujshedas one of the earliest intact examples in Arizona of this revised configuration. As such it is a noteworthy remnant of early AHD concrete bridge engineering.

NAllONLV REGISTER NPLUATlON

TECHNOLOGKL SIGNFKANCE HISTORKA SIGNFKANCE NATIONL REGISTER CRllERlA

- reverent$ the work of a master aruwiatsd with Onifcant parsons x CritarianA

- possassas h'gh mia fz values x assodated with Onifcant events a patterns - Werian B

x rcpcmntr a type, perioda method of conrvuction - cont!buter to hirtaical d&t - x G'ieimC

NATIONAL REGISTER RJGlBUN

hddually eligble x yes - no

cmubuter todmkt -yes no

ME4 OF SIGNFICANCE: Transportation; Engineering PERIOD OF SIGNIFICANCE: 1928-1964 THEMEIS): Transportation: Highways

W A S H B R I D G E swustur. b. 1020

Location Map

569 F R A S E R D E S I G N


Stone Avenue Underpass

county Fima inventory rumbw 07987 milepost 0.00 invmtory rout. Southern Padiic Rcdlroad location 3.4 ml North Jct SR 88 feature lntnsmed Stone Avenue cltyfvicinity Tucson USOS quadrangle Tucson dlstrkt 81 UTM refusme 12.502604.3565615

STRUCTURAL INFORMAllON

main span number 2 appr, span numbor 2 degree of skew 29 main span length 25.0

strudure length 76.0

roadway width 49.0 strusbre width 50.0

HISTORICAL INFORMATION

main pantype 237

appr, span type 201 guardrail typo wporstructue concrete dgld frame subsr~blre concrete abutments, wingwalls and piers flwrfdscking ballasted rcdlrocrd grade over concrete slab other features MMon Style awhitectuml treatment, with curvilinear

parapet and arched copings: pierced concrete hand& metal sconce lights

consru4hn date 1936 designufengineer Arizona Highway Department projcci number NRM 9 builduf~ntractor M.M. Sundt Construction Company, Tucson AZ information source ACOT M g e r e c o h strumre owner City of Tucson al tuakn datds) altoratbns

NATlONPL RKjlmR EVALUATION

For addiknal information, see "Vehicular Brldgea in Ariwna 1-1964" NaUonal Reglswr Multiple Prop* tyurnontakn Form

NRHP digibilii Ilsted NRHP crituia A- B- C L rlgnlf. statement well-preserved example of 1930s AHD d t e c t u m l

trecltment on gmde w.wraUon

FORM COMRmD BY

Clayton B. Fraser, Prindpal FRASERdesign 420 South County Rwd 23E Loveland, Colorado 80537 31 Oaober 2004

570 FRASERDESIGN

STONE AVENUE UNDERPASS s w w e Na 7987

PHOTO INORMPTION

dew of phom; Februq 2003 v*w di.ction: northeast northwest phom m: 03.02.274 03.02.275

S T O N E A V E N U E U N D E R P A S S

CONSmUCTlON HISTORY

In 1867 the Territorial Legislature designated Tucson as the territorial capitol, which the town kept for ten years. After the arrival of the Southern Pacific Railroad in 1880, Tucson found prosperity as a supply point for mines in southern Arizona and Mexico. The railroad provided a vital transportation link as it passed through the city center, and heavy traffic on its line posed logistical problems for travel on the streets, sna rhg trafficand creating dangerous on-grade c r o s s i s These problems increased considerably with the proliferation of motorcars after 1910.

In 1916 the City of Tucson built a grade separation at Fourth Avenue [84531. Fourteen years h e r , in 1930, the city built a similar underpas at Sixth Avenue [79881. The agency responsible for a thiK( grade separation in downtown Tucson-at Stone Avenue-was the Arizona Highway Department. Early in 1934 the highway department drafted plans for this structure, which would carry US 89 beneath the rdroad tracks. The Stone Avenue Underpass was comprised of a span for each double lane of vehicular traffic, with smaller barrels on both sides to accommodate pedestrian sidewalks. The skewed moin barrels were 25-foot concrete rigid frames. The structure featured a Mission Style architectural treatment, withcudinear parapets andarched copings, decorative iron l m p s hung from sconces, concrete guardrails with decorative cutouts and cast concrete cartouches prominently mounted on the spandrels of both sides. In 1935 AHD contracted with the M.M. Sundt Construction Company under project NRM-9 to build the Stone Avenue Underpass. TheTucson contractor completed the structure in January 1936. Since hat time, the Stone Avenue structure has functioned in place without substantial alteration. It no longer carries US 89 and has recently undergone a substantial rehabilitation.


Unlike bridges, which were typically located in rural settings, Arizona's urban grade separations were usu- ally designed with consideration of their aesthetic impclct. Most featured architectural treatments-either revivalist or modernist- intended to integrate the structures within their urban settings. The Fourth Avenue Underpuss features relatively strcdghtforward classical revival detcdling. The Slxth Avenue Underpass, in contrast, features an eclectic expression that intermingles Egyptian Revival and Classical Revival elements. The Stone Avenue Underpass displays mcdnline Mission Style det&g. A prototypical Arizona style, this was an architectural treatment that AHD used for several of its underpasses undertaken during the Great De- pression. These three bridges form a group of urban structuresthat is unique in Arizona. They are significant for their well-preserved architectural expression.

NAllONAL REGISTER EVALUAllON

TKHNOLOGKL SIGNFKANCE HISTORICAL SIGNFKANCE NATION& REGISTER CRITERIA - rapsssnts 6s work of e master - arxriated vdth Onikant p160n6 Cntsiin A

- prmeuer high Mirtk values - a m h t e d with enifcant events w patterns C m e i i B

x repteents e type, perbd w method d conrwuctian - - cm*utas to hktcnal & k t x CriterhC

NAnow RE~ISTER EUGIBUTY AREA OF SIGNRCANCE: Engineering vrdvrlually sllgble x yes - no PERIOD OF SIGNFKANCE: 1936-1964 conthutar to & k t -yes no THEMEN Transportation: Highways


STONE AVENUE UNDERPASS ~vucma Na 7987

Losation Map

573 FRASERDESIGN

STATE OF ARIZONA HISTORIC PROPERTY INWORY FORM

Sixth Avenue Underpass

county Pima inventory number 07988 mllspoat 0.00 inventory r o m Southern Pa& Rcdlroad iocatbn 3.2 mi North Jcl SR 86 feabre intersectad 6th Avenue citykkinity Tucson USGS quadrangle Tucson district 81 VTM referam 12.502902.3565388

main wan numbw 4 appr. span number 0

degrea of skew 45 main span lsngth 14.0 strusbre length 42.0

roadway width 80.0 m w e width 88.0

main p a n typ 332

appr. span type guardrail type

r u p u s t r w o steel I-beam stringer substrmre concrete abutments, wlngwalla and plers wlth

arched mnfflevera floorldecklng ballasted &cud grade over concrete slab other featwes EoyuUan Revlval Stvle mchitedural treahnent, with

&<concrete squashed balusters and bud mpltals; cast iron light standards; paneled concrete sidewalk

m n s t r h n date 1930 ddgnerlenglnm Tucson City Englnwr p r o j e number bui lderl~tracmr Lee Moor Conbadng Company, El Paso TX information sourw dty M g e records strurmre owner City of Tucson altsration data($) altuakns

NATIOW REGlmR EVALUAION

For additional infwmatbn, 500 "Vehkular Bridges in Arhna 1880.1964' Natbnal Registu Mulble Roputy Documentatbn Fwm

NRH eligibility Ilsted NRHaituia A - 0- C X signif. statement well-preserved example of architectural tredment

on urban gmde eeporotion

FORM COMREM BY

Clayton B. Fmser, hlndpal FRASERdedgn 420 South County Road 23E Loveland, Colorado 80537 31 Cctober 2004

574 FRASERDESIGN

S I X T H A V E N U E U N D E R P A S S

RlOTO INORMATlON

d m of phota: F h c p y 2333 view northeast northwest phata na: 03,02270 03.02.271

S I X T H A V E N U E U N D E R P A S S

CONSTRUCTlON HISTORY

The settlement of Tucson has its origins in antiquity, with several waves of occupation by Spanish, Mexican, Mormon andCdholk contingenkbefore the United States took ~ossession of the region under theGadden Purchasein 1856. In 1867the~errltorialle&l~~nated~~8onastheterrito~~lpitol, whichthe town kept for ten years. After the arrival of the Southern Padk Rollroad in 1880, Tucson found prosperity as a - -

supply point for mines in southern Arizona and Mexico. The rollroad provided a vital transportation k k as it ~usaed through the dty center, andheavy trafficon itsline posedlogisad problemsfor travel on the streets, snarling traffic andcreaUng dangerous ongrade crossings between pedestrians, wagonsandtrains. These problems increcrsed considerably wlth the proliferdon of motor- dter 1910.

In 1916 the City of Tucson built a grade sepcnatlon at Fourth Avenue t84531. Twelve years later dty enfieer Glenton Sykesdesignedadmjlar underpcrssfor &&Avenue. Sykes's shcture was made upof two 14-foot- long steel stringer spans supported by concrete abutments and pier. One lane of trcdflc pussesbeneath each span. At 88 feet, the underpass was not as wlde as its predecessor. It featured a vaguely Egyptlan Revival d t e c h u a l treatment, with squcrshed concrete balusters and bud cqitals, paneled concrete pcmpt waUs cmd cast iron lamp standcrrds lining the sidewalks that pussed beneath the spcms on either side of the roadway. In May 1930 the dty conhcted wlth the Lee Moor ConhcUng Company of El Paso, Texas, to build thia structure. Moor's crew completed work on the Sxth Avenue Underpuss later that year. It hcm functioned in place h c e with no substanhl alterdons.

SlGNlFlCANCE STATEMENT

Unlike hidges, which were typlwlly lomted in rural settings, Arizona's urban grade separations were usu- ally designedwithconsiderallon of theiraestheticimpuct Most fecrturedm&teduraltr&en~itherrevi- v&t or modernist- intended to integrcrte the stnrctures within their urban settings, The Fourth Avenue Underpuss features relatively straightforwcnd classical revival detailing. The Sixth Avenue Underpass, in contrast, features an ecledic expression that intermingles Egyptlan revival and classical revival elements. These two bridges, along with the W o n Style Stone Avenue Underpass [79871, built in 1936, form a group of urban structures that is unique in Arizona They are signiflccmt for their well-preserved dtectural expression.

NATIONAL REGlmR EVALUATION

m OF S I G N F K ~ Engineering PERIOD OF SKJNFICANCE: 1930-1964 THEW): Transportation: Highwcrys


S I X T H A V E N U E U N D E R P A S S suucoln NO. 7988


HISTORIC BRIDGE INVENTORY Cienega Bridge

PROPERTY ICENllFKATION

county Rma inventory rmmba 08233 milopst 0.W imntory route Mamh Station Rwd location 6.1 mi N Benson Hwy foahro intorsoctod Cienega Creek & Railroad citylviclrity V d U S 5 quadrangb V d distrki 81 VIM r d u m 12.533437.354267s

STRUCTURAL INORMATION

main span numbu I appr. span number 4 dqrea of sksw 0 mein span lmgth 148.0 structure length 278.0 roadway width 20.0 struaure width 23.2

main span type 11 1 appr, span type 101 guardrail typo 9 supu*uzture concrete two-& open-spandrel arch aubavucnxe concrete abutments, whgwah and piers flwrldecking concrete deck with aaphalt overlay othw foahros moulded concrete guardKdls w/ paneled paKlpet

w a h and s q u m concrete balusiers

HlSTORlW INFORMATION

consruchn dab 1921 d e s l g ~ l n g l ~ Arlzona Highway Depmtment project numbw FAP 18 buildalwnvactw EngM & Rerce information sow- ACOT bridge records *&r. o w w Pima County alteration dato(s) 1989 alarationr guadwh replaced

NATIONAL REGISTER NPLVATION

For additional infwrnafion, soo "Vohiilar Bridges in Ar ima 1880-1964" National Regirtw Multiple P r o m DosumentaU~n Form

NRHP digblity listed N(HPalwla A x 0- C~ signif. sta- we~-preaewed, long-span example of uncommon

structural type

Clayion B. Fraser, Prindpcrl FRASERdesign 47J South County Rwd 23E Lowland, Colorado 80537 31 October 2W4

C I E N E G A B R I D G E svw NO. 8293

MX) INFCXM4llON

d m ot awra: F e h w Dl03 -dh~aon: south northwest - n u 03.02.102 03.02.104

FRASERDESIGN

CIENEGA BRIDGE swume N a 8293

CONSlRUCTION HISTORY

with bqucrl funding from a ~ i m a ~ o u n t y bond issue, the ~ochise~ounty ~ o a d Fund and Federal~id~oject 18, the Arizona Highwciy D e m e n t in 1920 began constructlon of a portion of the Borderland Highway . .

across southern~*ona. l'he27%-mile-longse&n e x t e n d e d b e t w e e n & n s o n a n d ~ d o n d i n c l ~ or crossing of rugged ClenegaGmyon near Vd, just east of the Southern Pacific Roilroad bridge here. For - -

this, AHD engineen designed a longapcm concrete cuch over the canyon withatwo-spcm concrete girder viaduct over the rcdlroad trucks. Extending 146 feet. the open spcmdrel cach was comprised of two tcrpered rib that sprung from concrete foundations with spread footings. These rb supported a series of concrete columns whichin turn supportedtheconcretedeck Thedeck warrboundedonbothsides by concrete g u d - rails with square Musters and pcmeled bulkhe&.

After completing the drawings for the bridge, AHDdivided the constructlon into five sections. The grading and surfacing were undertaken by state work forces and contradon Gocdman & M e d and Eckerman & Chcrmbers. The contract for Section F-the Cienega Bridgewent to Tucson contractors English & Fierce. Using concrete ond reinfordng steel provided by the k h w w d e m e n t , the contractors completed the . .

stru&in b arch 1921 for acoit of a h more thcm $40,600. The~ienegaBridge d e d mob& traffic on the highway (later redesignated US 80) una construction of Interstate 10 in the 1960s. Today the Cienega Bridge bears intermittent local t d c . The bridge's superstructure remains unaltered, but its g & d d s hwe been replaced with a modlfied Jersey h r i e r configuration.

SIGNIRCANCE STATEMENT

In 1919-1920 the AHD bridge depdment designed three almost idenbbal open spcmdrel concrete urches for Arizonahighways: the CienegaBridge ondbridgm over Queen Creek [&I in PlndCounty ond Hell Om- yon [&] in Yay& County. The design of the Hell Omyon bridge was later chcmged, and the Cienega and Queen Creek structures were built in 1920-1921. Both have survived largely unaltered. Of the three, the Cienega Bridge h the longest spcm. Additionally, it is the oldest of the sunriving open spcmdrel arches in the inventory. As an excellent example of an uncommon shctural type and anintegrallink on the region- ally important Borderlmd Highway, the Cienega Bridge ts one of Arizona's more historically ond techno- log idy significant vehicular structures. Replacement of the g u ~ h ~ e d t h e b r i d g e e s structural integrity somewhat, but the sensitive design of the replacements minimizes the impact of this recent construction.

N4TION.N REGISTER NPLUATION

AREA OF SIGNIWCE: Transportaton; Engineering PWGDOFSIGNRCWZ 1921-1964 W M ~ Transportdon: Highways

5BO F R A S E R D E S I G N

C I E N E G A BRIDGE swwwe NO. 8293

STATE OF ARIZONA HISTORIC PROPERlY INVENTORY FORM

Fourth Avenue Underpass

PROPERTY ICENllFKATION

county Pima inventory numbw 08453 milqwst 0.00 inventory routa Southern Padfic RcdLcad location North of Toole Avenue feakre ihtarsectad Fourth Avenue cityMcinity Tucson USGS quadrangle Tucson dimkt 81 UTM r.fwnr* 12.503175.3565134

STRUCTURAL INFORMATION

main span nurnbw 4 appr, span number 0 dogroo of skew 0 main span length 12.0 srumre length 46.0

main span type 103 appr. span type guardrail type

w p e r m w e concrete deck substrusture concrete abutments, wingwalls and piers

roadway width 0.0 srumre width 257.0

flowldacking railroad ballast bed over concrete slab othw features paneled concrete Krmpe$ and ddewalls; ccmt

concrete columns; chain handrda with paneled concrete posts

HISTORICAL INFORMAllON

construction date 1916 dwignerlenginea Tucson City Engineer project number buiidm-Icontractor

information souce dty bridge records strumre owner City of Tucson altaration datdd alterations

NATIONAL REOlmR EVALUATION

For additional information, sou "Vehdar Bridgw in kiwna 1880-1964" Naknal Register Multiple Property Docunsntirtbn Form

invontory~wa 5'2 NRH' ali&ility listed NRWcrikrla A B- C~ slgnif. stsamm Arizona's oldest urban grade -ration

FORM COMRETED BY

Clayton B. Fraser, Rindpal FRASERddgn 420 South County R o d 23E Loveland, Colorado 80537 31 Odober 2004

582 FRASERDESIGN

F O U R T H A V E N U E U N D E R P A S S slrwuxe ~a 8453

MOT0 INFORMAllON

dam of phota: February 2003 v*w t b northwest northecmt $dona: 03.02.265 03.02.269

FRASERDESIGN

FOURTH A V E N U E UNDERPASS Suucturs No. 84.53

CONSTRUCSION HISTORY

The settlement of Tucson has its origins in antiquity, with several waves of occupation by Spcmish, Medam, Mormon ondMolic contingents before the Unitedstates took possession of the region under the Gadsden FJutdxwin 1856. In 1867the~erritorial~egislatmd~nded~ucson as the territorialcapitol, whichthe town kept for ten y e a . After theorrival of the Southern Pcrdflc Rcdlroadin 1880. Tucson found prosperity as asup- ply point for mines in southern Arizona ond Mexico. The Kdlrod provided a vital trcmsportdon link ag it p s e d through the dty center, ond heavy trcdflc on its line posed 1ogisU.d problems for travel on the streets, sncaling tndfic ond creating dangerous on-grade crossings between pedestrians, wagons cmd trains. h s e problems increased considerably with the proliferdon of motorm after 1910.

In 1913 the dty moved to se-e Fourth A v e n u m major thoroughfore in downtown Tucson-from the &adby constructing a grade sepcdon to c. Thedesign for the s h c h m was com~leted in June 1913 by L.R. Walker in behalf of Tucson Clty Engineer J. Ruthmuff. AS delineated by . - Walker the structure was comprised of two 12-foot-long, skewed concrete slabspcms, supportedby concrete abutments and pier. One lone of trcdflc p s e s beneath each s p . The underpccss was wlde-almost 260 feet wide-to ac~omrncdde the rcdlyord~it d e d 1t featureda~lassicalrevival~chiteduraltreatment, with recessed redongdm p e l s cast into the concrete s i d e d , s p d r e l s and w t s . A series of three-foot- tall concrete posts ccaries two heavy chains that ad ashcmdrdsbetween the streets ond the pedestrian sidewalks that h k e d them on both sides. The structure was completed in 1916. Since that Ume, the Fourth Ave- nue Underpas hcs d e d dty street trcdfic, in essentially undtered condition.


Unlike baldges, which were typically locded in rurcrl settings, Arizonds urbm grude s e m o n s were usu- ally designed with consideration of their aesthetic impact. Most featured c u c h i t d treatments-- either revivalist or modernist- intended to integrate the structures w i t h their urban settings. The Fourth Avenue Undepms features relcrtlvely simple, c l a s M revival detcdllng. It is todcry distlngulshed ag Arizonds oldest dateable urban made serwation. It is a companion structure to two other historic d e sewrations in downtown ~ucsin . The Sixth venue under& [79881 features cm e c l d expression that intermingles Egyptian revival and classical revival elements. These two bridges, along with the Mission Style Stone Ave- n&Unde-s [79871, built in 1936, form a woup of urbm st&wes that is unique in ~ r i k n a . They are signifimt for their well-preserved cuchitecturcrl expression.

NATIONAL EGISTW W A T I O N

ECHNCXOGKBLSIGNRCANCE HISTORKBL SffiNFWNE NATIONAREGIFIER CRIIWY

- r w m n e tho wak of a mstw - auwbted with &n'kmt ~ I O I U - x W n A

- pea- li& & valwr - x -ht.d m% anrunt m n t s u patterns - G k b n 8

rn OF SIGNW~E: Tmsportdon; Engineering pWl0D OFSffiNIRCANCE: 1916-1964 M E M I ) : Tronsporbrtlon: Highways

FOURTH AVENUE UNDERPASS S W Y C P ~ ~ ~ NO. MU

Location Map

Documents

Arizona Historic Bridge Inventory - azdot.gov · somewhat shallower girders, to create greater under-bridge clearance. This Wash Bridge uses this latter design