Rearview Video System as Countermeasure for Trucks Backing Crashes

Transcription

1 Rarviw Vido ystm as Countrmasur for Trucks Backing Crashs Evaluating th ystm s Effctivnss by Controlld Tst Chanyoung L, Achillas Kourtllis, Pi-ung Lin, and Ptr su In gnral, th opration of larg trucks involvs many diffrnt typs of manuvrs. Th backing manuvr, in particular, rquirs a highr lvl of drivr attntion bcaus of th limitd rar viw. A growing numbr of trucks in th Unitd tats ar quippd with a rarviw vido systm (RV) that can hlp th drivr s much of th ara bhind th vhicl. An RV consists of on or mor camras and on monitor. It is xpctd that an RV can hlp drivrs rduc potntial backing crashs. To valuat th ffctivnss of th systm, this study prformd a controlld drivr tst with 45 truck drivrs. Th tst usd thr backing manuvrs and a pdstrian dummy for obsrvation of potntial crashs. Th rsults showd that th us of an RV incrasd th stop rat of th drivrs during th straightlin backing manuvr by 46.7%, which could b intrprtd as an incras in th odds of avoiding potntial backing crashs during th backing manuvr. Th stop rat incrasd 4.4% and 17.8% for th offst right backing and ally dock backing manuvrs, rspctivly. Drivr ag, commrcial driving xprinc, and xprinc with an RV showd no statistical association with th incrasd stop rat, which mans an RV can b adoptd by drivrs quickly. In gnral, drivrs showd positiv attituds toward using an RV, and mor than 90% of rspondnts agrd that an RV could rduc th rar blind spot for larg trucks. In gnral, th opration of larg trucks involvs many diffrnt typs of manuvrs. Th backing manuvr, in particular, rquirs a highr lvl of drivr attntion du to limitd rar viw. Most trucking companis hav a policy that ncourags drivrs to visually chck th rar of th vhicl bfor prforming a backing manuvr, rgardlss of th backing distanc, and to us a spottr who can stand outsid th vhicl to nsur safty during th manuvr. A growing numbr of trucks in th Unitd tats ar quippd with rarviw vido systms (RVs), which can hlp a drivr s much of th ara bhind th vhicl. RVs consist of on or mor camras and on monitor. Thy provid th drivr with a rar viw of th vhicl to b usd, similar to a rarviw mirror in a passngr car. It is xpctd that an RV can hlp drivrs rduc potntial backing crashs. inc truck-backing crashs ar rar vnts, and dtaild data ar not asily availabl, a wll-dsignd controlld tst can b a vry ffctiv mans to assssing th ffctivnss of an RV as a countrmasur C. L, A. Kourtllis, and P.-. Lin, Cntr for Urban Transportation Rsarch, Univrsity of outh Florida, 4202 East Fowlr Avnu CUT100, Tampa, FL P. su, Florida Dpartmnt of Transportation, North McKinly Driv, M , Tampa, FL Corrsponding author: C. L, cyl@cutr.usf.du. Transportation Rsarch Rcord: Journal of th Transportation Rsarch Board, No. 2194, Transportation Rsarch Board of th National Acadmis, Washington, D.C., 2010, pp DOI: / for truck-backing crashs. This study prformd a controlld drivr tst with thr diffrnt typs of backing manuvrs. PREVIOU TUDIE A numbr of studis hav bn conductd to addrss th problm of backing crashs in rlation to all vhicls, including light, mdium, and havy trucks. Ths past studis hav indicatd that possibl countrmasurs for backing crashs ar proximity snsors and vido camra tchnologis. Vido camra systms wr first introducd in th 1980s as a countrmasur for crashs involving larg mining dump trucks. Th majority of prvious studis prformd static tsts. Th systm undr invstigation was installd on th vhicl, and whil th vhicl was not moving, objcts or pdstrians movd around th vhicl to obtain th rspons of th systm (1 5). Mor advancd rsarch fforts includd drivr simulator tsts, whr th drivrs wr askd to driv a simulatd vhicl and rspond to crtain stimuli. Th obsrvation of th drivrs was th primary objctiv of ths fforts. Th only study that prformd dynamic tsts is dscribd in Wirwill t al. (6), whr th drivrs drov an xprimntal truck quippd with th systms undr valuation and wr askd to prform crtain manuvrs, with and without th systm, in sparat runs. Tabl 1 summarizs th history of ths studis and thir findings. Th main factor missing from most of th rviwd studis was th valuation of th drivr undr xprimntal scnarios that simulat ralistic conditions. In addition, most studis did not tst th systms undr conflict scnarios. This study focusd on crating th rquird conflicts with pdstrian dummis and stationary objcts to obsrv th drivr s raction and th outcom of th conflict (crash or no crash). Th latst updat from is an advanc notic of proposd rulmaking initiatd in 2009 to amnd Fdral Motor Vhicl afty tandard 111: Rarviw Mirrors, to improv a drivr s ability to s aras to th rar of a motor vhicl in ordr to mitigat fatalitis and injuris associatd with backovr incidnts (11). CONTROLLED TET DEIGN On of th most important aspcts of having an RV is to hlp th drivr idntify potntial hazards instantanously whil backing, thus hlping th drivr to ract mor quickly and potntially avoid backing crashs. To tst th ffctivnss of th systm in this aspct, th dtction of potntial backing hazards was tstd by introducing an objct or a pdstrian dummy in th backing path. Thr diffrnt backing 55

2 56 Transportation Rsarch Rcord 2194 TABLE 1 istory of tudis Rlatd to Rar-Objct Dtction Tchnologis (1, 3 5, 7 10) Yar Agncy Titl Findings A tudy of Commrcial Motor Vhicl Elctronics- Basd Rar and id Objct Dtction ystms ardwar Evaluation of avy Truck id and Rar Objct Dtction ystms Exprimntal Evaluation of th Prformanc of Availabl Backovr Prvntion Tchnologis Evaluation of Prformanc of Availabl Backovr Prvntion Tchnologis for Light Vhicls Exprimntal Evaluation of th Prformanc of Availabl Backovr Prvntion Tchnologis for Mdium traight Trucks Us of Advancd In-Vhicl Tchnology by Young and Oldr Early Adoptrs Dvlopmnt of Prformanc pcification for Camra- Vido Imaging ystms on avy Vhicl On-Road tudy of Drivrs Us of Rarviw Vido ystms This study dalt with mirror and snsor systms usd for sid and rarobjct dtction on markt-rady and prototyp systms. Rsults showd that thy hav potntial in hlping drivrs avoid crashs. This is th first tim a vido systm is valuatd for its potntials in truck crash avoidanc along with snsor systms. Rsults showd that all systms improv drivr potntial in avoiding crashs. In this comprhnsiv study, mirror, snsor, and vido systms wr tstd for thir prformanc on UV-typ vhicls. Rsults showd that vido systms hlp th drivr dtct pdstrians bhind thir vhicls bttr than othr systms. This study, similar to th prvious, tstd th sam systms on light vhicls. Th outcom was that th vido systms prform bttr in hlping th drivr but do not warn th drivr of potntial dangr. Th sam study was prformd for mdium trucks. Th outcom showd that vido systms ar th most rliabl to show objcts bhind a truck. This study showd th diffrncs in ag with th us of snsor and camra systms. It also showd that drivrs ovrstimat th ffctivnss of th systms and ar mor likly to back fastr and mor carlssly whn having th systm. This study, th latst of its kind, tstd camra systms for diffrnt locations on th truck, to improv visibility and potntially rplac mirrors. This study includd dynamic tsting of systms with drivrs prforming backing manuvrs. Th latst naturalistic study of its kind collctd drivr bhavior data for a month from minivan drivrs. Th rsults showd that th ffctivnss of th vido systms is only about 20% and th drivrs us th systms but not in an fficint mannr to avoid all potntial crashs. manuvrs wr tstd for both trucks with an RV and thos without an RV. traight-lin Backing Manuvr Th straight-lin backing manuvr is th most typical backing manuvr in a drivr s vryday routin: ing and parking th truck at a loading dock to load or unload goods. As shown in Figur 1, th starting of th truck was 140 ft from a rctangular box. Th drivr had to back th truck straight through th box without touching any of th cons or passing on top of any boundary lins and stop aftr th full lngth of th truck was out of th box. As shown in Figur 1, whn th back of th trailr rachd th lin conncting th first two cons (65 ft from th nd ), an xaminr crossd bhind th trailr prpndicular to th truck s path. Th xaminr, who was carrying a stack of two cons (3 ft high), passd at normal walking spd, thn droppd th bottom con within th cntr box in th path of th backing truck and continud walking out of th box whil carrying th scond con. This was don so that if th drivr saw in th sid viw mirrors th xaminr passing through, thy would not b abl to dtct immdiatly that th xaminr droppd a con sinc it appard that th con was transfrrd all th way to th othr sid of th box. Th manuvr was prformd twic, onc without th us of an RV and onc with it, in a random ordr for ach drivr. Obviously, whn th drivr had th RV on and was watching th monitor, th drivr could clarly s that th xaminr droppd a con and thrfor stop th truck bfor hitting th con. If th drivr stoppd for th con, th distanc from th back of th trailr to th con was masurd, rcordd, and notd as a stop. If th drivr did not stop, it was notd as a hit. This happnd on both occasions (whn a drivr was using th systm, and whn a drivr was not using th systm). Figur 2 shows snapshots of th actual tsting. Offst Right Backing Manuvr This manuvr rquird th drivr to start from a similar to th first manuvr, backing th truck and curving to th right towards a similar box, as shown in Figur 3. Th nd of th box was a loading dock, and th drivr was askd to stop th truck at a distanc of 3 ft from th door. During this manuvr and whn th back of th trailr was locatd approximatly 65 ft from th loading dock, an xaminr introducd a pdstrian dummy in th shap of a small child 3 ft high. Th pdstrian dummy was rmotly controlld and strd from a saf distanc. Th dummy was introducd at approximatly 20 ft from th back of th trailr. If th drivrs stoppd for th dummy, th distanc btwn th dummy and th trailr was masurd, rcordd, and notd as a stop. If th drivrs did not stop, it was notd as a hit. Aftr this, th drivrs continud th manuvr, and th distanc from th back of th trailr to th loading dock was masurd and rcordd. Ally Dock Backing Manuvr This manuvr rquird th drivrs to th truck at a 90 angl from a box lading to a loading dock and str th truck into th box again, parking th truck 3 ft from th dock. A schmatic diagram is shown in Figur 4. As with th offst right backing manuvr, whn th trailr was approximatly 65 ft from th dock, a pdstrian

3 L, Kourtllis, Lin, and su 57 TETING PROCEDURE Th tsting procdur follows: Whn rar of trailr was hr th con was droppd in th truck s backing path 20 ft back Exprimntr s walking path path starting 12 ft 140 ft 65 ft 1. Th participating drivrs wr askd to rad and sign a drivr informd-consnt form that xplaind th procdur of th tst, th risks and discomforts, th bnfits to th drivr, th xtnt of anonymity and confidntiality, th compnsation, and thir rights, and thn confirmd thir prmission to participat in th tst. Each drivr was assignd a numbr that would srv as an idntifir for all stags and forms of th tst for anonymity purposs. 2. Th drivrs wr thn givn a flyr showing diagrams of th thr manuvrs that wr includd in th tst, with dtails for ach. Each drivr ntrd an quippd truck, a trling day cab tractor with a 34-ft trailr. A scond xaminr was insid th truck to guid th drivr through th manuvrs. 3. Th drivrs wr askd to prform two sts (with and without a rarviw systm) of thr diffrnt manuvrs (straight-lin backing, offst right backing, and ally dock backing). To minimiz potntial bias, th ordr of th six manuvrs for ach drivr followd a prgnratd random numbr tabl. Thrfor, ach drivr compltd th manuvrs in a diffrnt ordr. 4. Anothr two xaminrs wr stationd outsid th truck to obsrv, rcord, and control th tst dummis. 5. Aftr compltion of all six manuvrs, th drivrs wr askd to complt a survy to provid thir fdback on th systm. ANALYI OF TET REULT FIGURE 1 dummy was introducd to obsrv th raction of th drivr. If th drivr stoppd, th distanc from th dummy to th trailr was masurd, rcordd, and notd as a stop. If th drivr did not stop, it was notd as a hit. Again, th distanc from th dock at th nd of th manuvr was rcordd. DATA COLLECTION final traight-lin backing manuvr. Th data collctd from th xprimnt cam in two forms: (a) vido, audio, and snsor data rcordd on a digital vido rcordr and (b) obsrvations and masurmnts by th fild prsonnl takn during th tst. Th truck was quippd with thr camras. As shown in Figur 5, on camra (Camra 1) was installd insid th cabin nxt to th monitor to rcord th drivr s bhavior. A scond camra (Camra 2) was installd at th top of th cargo box trailr aimd down at an angl of 60 to th horizontal. A third camra (Camra 3) was installd undr th brak lights of th trailr at an angl of 0 to th horizontal. Camra 3 was usd to provid vido fd to th drivr during th tst. In total, 45 drivrs participatd in th controlld tst. Th avrag of thir commrcial vhicl driving xprinc was 10.9 yars, and 15 drivrs had prvious xprinc with RV. On avrag, ach drivr took approximatly 21 min to complt all six manuvrs. First, diffrncs in th stopping rats (not hitting th con or th dummy) wr tstd with and without an RV. Tsting this null hypothsis is th sam as tsting th diffrnc of th probabilitis of stopping with and without an RV ( 0 : P 1+ = P +1 and 1 : P 1+ > P +1 ). whr is stop and is hit. Without RV With RV P 11 P 12 P 21 P 22 stop P1 + = P11 + P12 = Pr = W with camra P stop = P + P = Pr = O without camra Th data wr analyzd with only th drivr raction, including hit and stop information. Tabl 2 shows 2 2 contingncy tabl for th manuvrs. Estimations follow: = ( ) = d P P, ˆσ d ( ) P + P P P n

4 58 Transportation Rsarch Rcord FIGURE 2 traight-lin backing manuvr during tsting. A McNmar tst was adoptd for matchd paird data and to rport th p-valus from th null binomial probability distribution and th asymptotic calculations. McNmar tst statistics = ( P12 P21 )2 P12 + P21 χ 2df =1 undr null probability distribution. Th rats and variancs ar calculatd from th abov quations. As shown in Tabl 3, th prsnc of an RV incrasd th stop rat of th participating drivrs during th straight-lin backing manuvr by 46.7%, which can b intrprtd as th incras in odds to avoid potntial backing crashs during th manuvr. Th stop rat incrasd 4.4% and 17.8% for th offst right backing and ally dock backing manuvrs, rspctivly. It is important to not that th siz of th blind spot and th rquird ffort for both th straight-lin backing and th offst right backing manuvrs wr narly th sam in gnral, but th dummy objct was introducd in a diffrnt way for th two. For th straight-lin backing manuvr, th dummy objct (a con) was d dirctly bhind th vhicl, whras th dummy objct was movd from th sid of th vhicl for th offst right backing manuvr. Whn th objct was strd towards th back of th vhicl from th sid, th drivr had a chanc to spot it with ithr of th sid viw mirrors, but th objct was rlativly difficult to dtct whn strd from th right sid of th truck. Thrfor, th diffrnc in th rsults should not b intrprtd as a diffrnc in manuvrs. Rathr, it rprsnts a diffrnt lvl of ffctivnss of th RV to dtct objcts from diffrnt sids of th vhicl. Also, thr was a diffrnc in th incras of th stop rat for th offst right backing and ally dock backing manuvrs, although th sam mthod was usd to introduc th pdstrian dummy. It appars that th ally dock backing manuvr rquirs mor attntion and ffort by th drivrs to control th vhicl compard to th offst right backing manuvr and rsultd in mor opportunitis for th drivrs to miss th approaching dummy with th traditional sid viw mirrors. To tst th variabls having a significant ffct on th incras of th stop rat, a mathmatical modl was cratd. Insignificant variabls wr not includd. Four variabls manuvr typ, RV, and two intraction trms wr usd in th final mathmatical modl shown in Tabl 4 as follows:

5 L, Kourtllis, Lin, and su 59 Rarviw ystm Monitor Camra 1 Drivr Viw Camra starting 140 ft Camra 2 Whn rar of trailr was hr th pdstrian dummy was movd in th truck s backing path 20 ft back 65 ft final Camra 3 12 ft FIGURE 5 Location of RV camras. FIGURE 3 Offst right backing manuvr. starting path 70 ft Typ 2 cofficint rprsnts th diffrnc of log of th odds of hitting btwn M1 and M2 and Typ 3 cofficint rprsnts th diffrnc of log of th odds of hitting btwn M1 and M3. This final modl can rprsnt th probability of a backing crash basd on th controlld tst data as follows: ( ) ( ) = log Pr Y = 1 Pr Y = 0 α β X β X γx i X X i XX Probability of hitting: Whn rar of trailr was hr th pdstrian dummy was movd in th truck s backing path 20 ft back Pr Y = 1 whr 1 α+ β1x1+ β2x2+ γx3 ( ) = + = α+ β1x1+ β2x2+ γx X X X X X X3 FIGURE 4 Ally dock backing manuvr. final 12 ft 40 ft X X = M tsting 0 othrwis 1 M3 tsting = 0 othrwis 1 us RV X3 = 0 not us RV

6 60 Transportation Rsarch Rcord 2194 TABLE Contingncy Tabl Without RV traight-lin Offst Right Ally Dock Backing Backing Backing Total Backing With RV NOTE: = stop, = hit. TABLE 3 TABLE 4 Rsults of McNmar Tst Incras top Tst Typ P-Valu Rat (%) Varianc (%) traight-lin backing E Offst right backing Ally dock backing Total (45) backing tst E Final Mathmatical Modl Cofficint Estimat E Z-Valu Pr(> z ) Intrcpt ** Typ *** Typ *** RV *** Typ 2: RV * Typ 3: RV * p <.05, ** p <.01, *** p <.001. Equation Boxs 1, 2, and 3 prsnt th probabilitis of hitting an objct, which can b stimatd by using th abov modl. Equation Box 1 shows Manuvr 1, straight-lin backing; Equation Box 2 illustrats Manuvr 2, offst right backing; and Equation Box 3 shows Manuvr 3, ally dock backing. Furthr tsting was prformd to valuat if th incras in th stop rat was statistically associatd with th actual frquncy or duration of monitor glancs during th backing manuvrs. During th manuvrs, th drivrs usd th drivr sid mirrors, th RV monitor, and th passngr sid mirrors to prform thir backing manuvrs safly. Th glancing duration and frquncy for ach mirror or monitor wr diffrnt for ach drivr. To conduct th analysis, th vido data rcordd during th controlld tst wr analyzd by using softwar that multiplxs all camras at th sam tim in a singl scrn. Figur 6 shows a scrnshot from th Vido Log Analysis softwar. Th vido from ach camra can b sn in 30 frams/s. For vry fram, th drivr glanc was rcordd. Th vidos wr rviwd, and ach fram was countd with its corrsponding glanc location. A databas that includd all drivr manuvrs, total manuvr duration, glanc duration, and frquncy pr location was cratd. Tabls 5 and 6 show avrag frquncy and total glancing duration for ach mirror and monitor by manuvr. With an RV, drivrs did not rduc th frquncy of glancing at th drivr sid and passngr sid mirrors, but th total tim of glancing for EQUATION BOX 1 ( ) = + Pr hitting M1 with RV Pr hitting M1 without RV = = % % ( ) = + = = diffrnc of hitting rat for M1 with and without RV = % % = % EQUATION BOX 2 ( ) = Pr hitting M2 with RV Pr 1+ ( hitting M2 without RV) = = = % = = % diffrnc of hitting rat for M2 with and without RV = % % = 4. 44%

7 L, Kourtllis, Lin, and su 61 EQUATION BOX 3 ( ) = Pr hitting M3 with RV Pr 1+ ( hitting M3 without RV) = = = 2. 22% = = % diffrnc of hitting rat for M3 with and without RV = % 2. 22% = % both mirrors was slightly rducd. In gnral, drivrs took a littl mor tim to complt th manuvrs with an RV. owvr, thr is no statistically significant diffrnc in frquncy and duration of glancing at an RV monitor basd on prvious xprinc with RV. inc th duration of th backing manuvrs was diffrnt by individuals in th tst, th updatd frquncy (F*) was usd for furthr analysis as follows: F k duration of manuvr k * drivr t drivr F i drivr i i avrag duration of manuvr k t ( ) = ( ) ( ) drivrs whr F(K) drivri is th frquncy of drivr i watching th monitor during backing manuvr k. Th liklihood of hitting an objct with th monitor glanc frquncy was tstd as follows, and dtails can b sn in th following tabl: Cofficints Estimat td. Error z-valu Pr(> z ) Intrcpt Monitor glanc count or frquncy Odds ratio is dcrasd by th factor quals For th intrcpt s probability, p <.001. As sn in th following tabl, it appars that th liklihood of hitting an objct is mor closly associatd with th ratio of tim spnt watching th monitor during a backing manuvr. Th prob- ability of hitting an objct is rducd as th duration of looking at th monitor is incrasd. duration of looking at th monitor Mt = duration of backing manuvr whr Mt is th monitor glanc duration (tim). Cofficints Estimat td. Error z-valu Pr(> z ) Intrcpt Mt ignificanc lvl quals Odds ratio is dcrasd by th factor quals TABLE 5 Avrag Numbr of Glanc Frquncis pr Backing Manuvr Drivr-id Passngr-id RV Backing Manuvr Mirror Mirror Monitor Without RV traight-lin backing N/A Offst right backing N/A Ally dock backing N/A With RV traight-lin backing Offst right backing Ally dock backing FIGURE 6 Vido log analysis softwar. TABLE 6 Avrag Lngth of Glanc Duration pr Backing Manuvr Drivr- Total id Passngr- RV Manuvr Backing Manuvr Mirror id Mirror Monitor Tim a Without RV traight-lin backing N/A 65.5 Offst right backing N/A 60.3 Ally dock backing N/A 70.5 With RV traight-lin backing Offst right backing Ally dock backing a Total manuvr tim also includs pull-up tim.

8 62 Transportation Rsarch Rcord Numbr of Rsponss (Total 45) traight Lin Back Offst Right Back Ally Dock Back 0 trongly Agr Agr omwhat Agr omwhat Disagr Disagr trongly Disagr FIGURE 7 Do you fl mor comfortabl prforming a backing manuvr with an RV? In othr words, th odds of dtcting a potntial hazard during a backing manuvr with an RV could b highr if th drivr allocats mor tim to th RV. owvr, during th xprimnt it was obsrvd that th drivrs wr using th systm just as anothr mirror, thus looking at th imag with quick glimpss btwn sid mirror glancs. Just as with a mirror, it is clar that if th drivr is not looking at th xact tim whn th objct or prson is passing through th viw, th drivr will not s it. This is tru vn for an RV systm, vn if th systm has a much widr fild of viw than th two sid viw mirrors. As shown in Figur 7, th drivrs xprssd positiv attituds toward using an RV in th follow-up survy aftr th tst. Most drivrs agrd that th RV can hlp thm rduc potntial backing crashs. Furthrmor, mor than 90% of rspondnts agrd that RVs can rduc th rar blind spot for larg trucks. CONCLUION RVs ar xpctd to rduc potntial backing crashs, spcially for larg trucks. To valuat th ffctivnss of an RV in a controlld nvironmnt, w first rviwd prvious studis, including th history of studis rlatd to rar-objct dtction tchnologis. A comprhnsiv tst was dsignd and conductd that was diffrnt from prvious fforts. In this tst, an objct and a pdstrian dummy wr movd into th truck s backing path aftr th truck was moving to rprsnt mor ralistic scnarios. Thr diffrnt manuvrs wr includd in th final dsign of th controlld tst. Th tst was intndd to assss if th us of an RV can hlp drivrs idntify potntial hazards instantanously during a backing manuvr. Thr manuvrs straight-lin backing, offst right backing, and ally dock backing wr tstd with and without RV scnarios. Th rsults showd that th us of an RV incrasd th stop rat of drivrs during th straight-lin backing manuvr by 46.7%, which can b intrprtd as th incras in odds to avoid potntial backing crashs during th manuvr. Th stop rats wr incrasd by 4.4% and 17.8% for th offst right backing manuvr and th ally dock backing manuvr, rspctivly. Th diffrnc in th stop rat should not b intrprtd as a diffrnc in manuvrs. Rathr, it rprsnts a diffrnt lvl of ffctivnss of th RV to hlp drivrs dtct objcts from diffrnt sids of th vhicl. Drivr ag, commrcial driving xprinc, and prvious xprinc with an RV did not show any statistical association with th incrasd stop rat, which mans an RV can b adoptd by all drivrs quickly. Furthr analysis of th vido log rvald that th participating drivrs took a littl mor tim to complt th manuvrs whn thy had th RV. With th RV, th drivrs did not rduc th frquncy of glancing at th drivr sid and passngr sid mirrors, but th total duration of glancing at both mirrors was slightly rducd. owvr, thr is no statistically significant diffrnc in th frquncy and duration of glancing at th RV monitor basd on prvious xprinc with RV prior to th tst. Additionally, it was found that th liklihood of hitting an objct was associatd with th monitor glanc duration during th backing manuvrs rathr than th monitor glanc frquncy. In gnral, th participants showd a positiv attitud toward using an RV, and mor than 90% of rspondnts agrd that an RV can rduc th rar blind spot for larg trucks. Ovrall, this study confirmd that an RV can rduc potntial backing crashs for larg trucks by incrasing th odds of dtcting potntial hazards during backing manuvrs. REFERENCE 1. A tudy of Commrcial Motor Vhicl Elctronics-Basd Rar and id Objct Dtction ystms., U.. Dpartmnt of Transportation, Washington, D.C., Ruff, M. T. Evaluation of ystms to Monitor Blind Aras Bhind Trucks Usd in Road Construction and Maintnanc. Publication RI-9660.

9 L, Kourtllis, Lin, and su 63 NIO, U.. Dpartmnt of alth and uman rvics, Washington, D.C., Mazza, E. N., and R. W. Garrott. Exprimntal Evaluation of th Prformanc of Availabl Backovr Prvntion Tchnologis. Publication DOT , U.. Dpartmnt of Transportation, Washington, D.C., Mazza, E. N., and R. W. Garrott. Exprimntal Evaluation of th Prformanc of Availabl Backovr Prvntion Tchnologis for Mdium traight Trucks. Publication DOT , U.. Dpartmnt of Transportation, Washington, D.C., Mazza, E. N., and R. W. Garrott. Evaluation of th Prformanc of Availabl Backovr Prvntion Tchnologis for Light Vhicls. Publication , U.. Dpartmnt of Transportation, Washington, D.C., Wirwill, W. W., W. A. haudt,. K. Gupta, J. M. paulding, and R. J. anowski. Dvlopmnt of a Prformanc pcification for Camra Vido Imaging ystms on avy Vhicls: upporting Rsarch. Publication DOT , U.. Dpartmnt of Transportation, Washington, D.C., Garrott, R. W., M. A. Flick, and E. N. Mazza. ardwar Evaluation of avy Truck id and Rar Objct Dtction ystms. In ocity of Auto- motiv Enginrs Tchnical Papr ris. Papr No ocity of Automotiv Enginrs, Warrndal, PA, Jnnss, W. J., N. D. Lrnr,. Mazor, J.. Osbrg, and B. C. Tfft. Us of Advancd In-Vhicl Tchnology by Young and Oldr Early Adoptrs. Publication DOT , U.. Dpartmnt of Transportation, Washington, D.C., Mazza, E. N., F. Barickman., G... Baldwin, and T. Ranny. On-Road tudy of Drivrs Us of Rarviw Vido ystms (ORDURV). Publication DOT , U.. Dpartmnt of Transportation, Washington, D.C., Wirwill, W. W., W. A. haudt.,. K. Gupta, J. M. paulding, R. J. anowski. Dvlopmnt of a Prformanc pcification for Camra/Vido Imaging ystms on avy Vhicls: pcifications. Virginia Tch Transportation Institut, Blacksburg, Fdral Motor Vhicl afty tandards, Rarviw Mirrors: Advanc Notic of Proposd Rulmaking (ANPRM)., U.. Dpartmnt of Transportation, Washington, D.C., Th Truck and Bus afty Committ pr-rviwd this papr.