A Traffic Simulation in Japan

tECHNoLoGy

Simulation Program Aims to Model Trafc within Entire Cities

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or any transportation plannr or nginr who has vr wantd to know in advanc how changs in trac pattrns or mass transit s wold act congstion in an rban nvironmnt, hlp may soon b on th way. Rsarchrs Rsarchrs in Japan rcntly annoncd an noncd th dvlopmnt o a simlation program that thy claim can b sd to modl trac pattrns on th scal o a major city.  Jointly  Joint ly dvlopd by rsa rsarchrs rchrs at ibm ’s Tokyo Rsarch Laboratory and Kyo¯to univr sity, th sim simlator lator is known as th Larg-Scal Mlti-Agnt Trac Simlation Systm. Considrd th rst o its kind, th systm was cratd with th goal o simlating th driving bhavior o individals to an nprcdntd dgr. By simlating trac rapidly and on a larg scal, th systm can indicat how crtain changs in mass t ransit, tra c fow, fow, and trac rglations ar likly to infnc congstion. It can also assss th ct on trac o th opning o nw commrcial stablishmnts. Th systm combins two progra programs. ms. Th rst is th ibm Zonal Agnt-Basd Simlation environmnt, a propritary ramwork or bilding and rnning larg-scal simlations basd on th  Java program min ming g lang ag, dvlopd by Sn Microsystms, Inc., o Santa Clara, Caliornia. This program maks

it possibl to simlat vacations and othr larg-scal vnts. In act, whn applid to trac, th program can simlat th actions o mor than 1 mil lion vhicls at a tim. Th scond program—th ibm Mga Trac Simlator—oprats as an adjnct to th r st. Bcas it is capabl o modling actions on a smallr scal, it givs th ovrall modl a gratr  dgr o granlarity; that is, th trac simlator can modl activitis o individal drivrs, as wll as gnral trac fows and rots. According to th modl’s dvloprs, th ibm Mga Trac Simlator has bn validatd by comparing its ndings with th rslts o trac volm obsrvations mad in Kyo¯ to la st Oct obr. Th at month mont h th city condctd a program dsignd to ncorag rsidnts to driv lss, walk mor, and s mass transit. Dring that priod, th rsarchrs simlatd trac fows in th cntral ara o Kyo¯to, nco mpas sin g mor th an 32,000 roads and narly 23,000 intrsctions. Th modld rslts wr thn compard with actal trac data obtaind dring th xprimnt. “Th comparison o th simlatd val with th obsrvd showd a high corrlation btwn ths two mtrics, which indicats th s-

cint prdictability prdictability o or tra c simlator,” says Si Kato, a rsarchr at Tokyo Rsar ch Laborato ry. ib m’s Tokyo Th Larg-Scal Mlti-Agnt Trac Simlation Systm modls sch aspcts as spds, vhicl positions, distancs btwn vhicls, and th crvatr and gradint o th road on which a particlar vhicl is travling. Th simlator can vn accont or  common charactrist ics o yongr yongr and oldr drivrs. By adding crtain attribts to th modl, th rsarchrs can xamin what ct changs in trac might hav on, say, th gnration o carbon dioxid or  th potntial or accidnts. “Imagin “Imagi n having th ability to as congstion whil crtailing polltion and accidnts,” said Tor Ish Ishida, ida, a prosso pr ossorr at Kyo¯to uniun ivrsity, in a Jn 10 nws rlas issd by ibm. “ibm and Kyo¯to univr un ivrsit sity y hav ond a way to do this bor xpnsiv and disrptiv constrction and othr  changs chan gs impact i mpact Kyo¯to’s conomy and a nd its citizns,” h said. “This is an xampl o how tchnology tchnology can aid a id smartr dcision making. makin g.” ” Althogh th systm is not at prsnt bing sd to modl trac in any othr citis, th rsarchrs plan to propos its s in varios mnicipalitis, Kato says.  —Jay Landers

RESEaRCH BRIEF FISH EmBRyoS EmBRyoS uSEd to dEtECt potENtI potENtI aLLy HaRm FuL CHE mICaL S IN WatER  WatER 

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tam o rsarchrs at Prd univrsity has sccsslly sd sh mbryos jst a w days old to dtct th prsnc o potntially harml chmicals in watr. Th procss dtctd th chmicals at lvls low nogh to b dmd accptabl in drinking watr  by th u.S. environmntal Protction Agncy, according to a prss rlas issd by Prd in Agst. Th

trld, Ph.D., an associat prossor o  vidual embryos. In addition to atrazine, agricltral and biological biological nginring the research ocused on the heavy metal as wll as o horticltr and landscap cadmium cyanide and on pentachloroarchitctr at th nivrsity. phenol, an antiungal. Porterfeld said The tests proved that minute the approach could be used to detect amounts o such common pollutants as both naturally occurring and manthe pesticide atrazine cause changes in made pollutants, including biological the respiratory respirator y processes o fsh embryos weapons. A prototype o the process in the water, changes that can be could be ready or feld tests within our  detected within minutes by fber-optic  years, according accordin g to the release.