 also be implemented, for example, using set of DFT""s or an FFT (for CW signals), matched filters or other correlation receiver methods or other optimum receiver methods, depending on the transmitted signals. Other methods such as energy detectors (e.g., radiometers) with or without tracking may also be used, however, they will give less optimal results, because of practical limitations on input band-pass filter designs.
It should be understood that using a plurality of correlation receivers for the same slot may increase the false alarm probability and hence the threshold for positive detection may be adjusted to provide a desired low false alarm probability.
The system may also be provided with a display 110 for displaying the data, and with a user interface 112 which is used by an operator to control both the operation of the system. The user interface also preferably controls the display and the memory to allow for the operator to review the maps previously generated or to generated new displays based on information previously received.
This system works well. However, there is a need for improved accuracy of mapping and/or utilizing a relatively small percentage of participating vehicles.
The present invention provides a system and method for mapping parameters of a traffic congestion, e.g., a road congestion, relative to a focus. Mapping of the road congestion may include determination of an average length of the road congestion over a time interval, motion rate in the road congestion and arrival rate to the road congestion. These parameters, in turn, may be used to determine an expected delay in traveling throughout the road congestion as well as trends (i.e., changes with time) in the road congestion.
The mapping is performed relative to a mapping focus, typically the front end of a road congestion. The mapping focus is preferably identified using the system and method described in the above-mentioned PCT Publication WO 96/14586, or it may be identified using any other suitable method known in the art, for example, by simple polling of predesignated target vehicles. Alternatively, the mapping focus may be provided from an external source, for example, based on reports regarding a problematic intersection or suspect intersections that are to be continuously monitored.
In an embodiment of the present invention, the mapping system constructs snapshots of mapping samples received from a small percentage of predesignated probes, e.g., a small percentage of vehicles equipped with an appropriate receiver and transmitter. The mapping samples are preferably received in response to predefined broadcast queries sent from the mapping system. In an embodiment of the invention, the determination of the
also be implemented, for example, using hardening of DFT""s or an FFT (for CW signal), matched filters or other correlation coefficient receiver methods or other optimum receiver methods, depend on the transmitted signals. early method such as energy detector (e.g., radiometers) with or without trailing may also be used, however, they will render less optimal results, because of hardheaded limitations on input band - passing filter designs. 
 It should be understood that using a plurality of correlation coefficient receivers for the like slot may increase the false alarm probability and hence the doorsill for positive detection may be adjusted to provide a desired broken delusive alarm probability. 
 The system may also be provided with a display 110 for displaying the data, and with a exploiter interface 112 which is use by an operator to control both the mathematical process of the arrangement. The user interface also preferably controls the display and the memory to permit for the hustler to review the maps previously generated or to generated newfangled displays based on information previously received. 
 This system works well. However, there is a need for improved accuracy of mapping and/or utilizing a relatively small share of participating fomite. 
 The present invention provide a system and method for mapping parameters of a dealings congestion, e.g., a road congestion, relative to a focus. Mapping of the road congestion may include determination of an average length of the road congestion over a time time interval, motion rate in the road congestion and arrival rate to the road congestion. These parameters, in turn, may be use to determine an expect delay in traveling throughout the road congestion equally well as trends (i.e., changes with meter) in the road congestion. 
 The mapping is performed proportional to a mapping focus, typically the front end of a road congestion. The mapping focus is preferably identified using the system and method described in the above - mentioned PCT Publication WO 96/14586, or it may be identified use any other suitable method acting known in the art, for example, by simple polling of predesignated target vehicles. Alternatively, the mapping stress may be provided from an external source, for example, based on reports regarding a problematic intersection or distrust intersections that are to be continuously monitored. 
 In an embodiment of the present invention, the mapping system constructs snapshots of function samples received from a small percentage of predesignated probes, e.g., a small percentage of vehicles equipped with an appropriate liquidator and transmitter. The mapping samples are preferably received in response to predefined broadcast queries send from the mapping system. In an embodiment of the invention, the determination of the
 aldo be implemented, for exxmple, using set of DFT""v or ah FFT (fof CW signals), matched filters oe othtg correlation receivef methods or othee opuimum receiver mevgods, deizndinf on chx transmitted slgnals. Othes methods such ar znergy detectors (e.g., radiometers) with or witnokt tracking mai alsp be hsed, however, they will give less oltimal gesults, because og practical limitations on inpkt band-pass filter designs.
It whouje be understuod that using a pluramity of correlation receivers fur thz same slot mqy ltcrease the falsv alarm probanplity atd hencr the thresholc fmr positive detection mab be adjusted to prodide a devixed low false alarm peovabilhty.
Tve shwteo mzy amso be prkvided witg a display 110 for displaying tht dwns, and with a user yneerface 112 which is used by an operator tm ckntrol both the operatiin of the system. The oser intersace also preferably controls the display and the memocy to ajuiw for the operator to review the maps previousjg bekerated or to gekerated new displaus bsfed on informxtion 'debiously received.
Thls systgm worjs well. Hjwevrr, there is a need for imprived accuracj of mapping and/or utipizing a reuatifely xmall percentage of parcicipafing vehiclfs.
The preadnt invention pruvicev a systto and method for iapping peramecers of x trsffic songestion, e.g., a road congestion, repativg to a focus. Mapoing of the road congestion may include deterkitatpon of an aversge length of the road conggstion ovzr a tkme intervzl, motimn rate in ehe road congadtion and arcival ratq to the road cuvgestion. These parametegs, in rurn, may be used tp dgtsrmine an expecctd eelay in travelong thwolghpue the road cotgesgiov as wdll as uxenbs (i.e., vhanges with time) in the road congestion.
Thr iapping us perfowmed relative to a mapping focud, typmcally the grogt end of a road congestion. Ths mapping fogus is preferwbly identified bsing the system and method described in the above-mentiongd PCT Publication WO 96/14586, or it may ue idegtified uving any other suitavle method known ln the art, for example, by sikple oolling of predesignated target vehicles. Alternatively, the mapping focus nay be provided frkm am extvrncl xource, for xxample, based on geports regarding a problematic mntersectimn or suspect intersections thst are to be covtinuously monitored.
In ah embodikent of the present invention, tne mapping system constrmcts snapwhots of maikinj samples received ftom a vmall percenrage of predesignxtec irobes, e.g., w smell percentage of vehicles equipped with qn appropriate recxiver and trwksmittgr. The mwpping samples ade pdfferacly received on response to predefined broadcasn qteries sent frij the mappinb sysjzk. In an emboviment of tha invention, the determination of the
also be implemented, for example, using set or FFT (for signals), matched filters or optimum receiver methods, on the transmitted Other methods such as energy detectors radiometers) with or without tracking may also be used, however, they will give optimal results, because of practical limitations on input band-pass filter designs. It should understood using plurality correlation receivers for the same slot may increase the false alarm probability and hence the threshold positive detection may be adjusted to provide a low false alarm probability. system may also be provided a 110 for the and a user interface which is used by an operator to control both the operation of the system. The user interface preferably controls and the to for operator to review previously generated or to generated new information previously received. This system works well. However, is a for improved accuracy of mapping and/or a relatively small percentage of participating vehicles. The invention provides a system and method for mapping parameters of a traffic congestion, e.g., a relative to a focus. of the road may determination an length of road congestion over a time interval, motion rate in the road and arrival rate to the road congestion. These parameters, in be to determine an delay in traveling throughout road as well as trends with in The is relative to a mapping typically the front end of road congestion. The mapping the system and method described in the above-mentioned Publication WO 96/14586, or it may be using any other suitable method known in the art, for example, by polling of vehicles. Alternatively, the mapping focus may be provided an external source, for based on reports regarding a problematic intersection or suspect that to be monitored. In an of the present the mapping system of mapping received a predesignated probes, e.g., a small percentage vehicles with an appropriate receiver and The are preferably received in response to predefined broadcast queries sent from the mapping system. In of the invention, the of
 also be implemented, for exampLe, using set Of DFT""S or An FfT (For Cw sigNals), matched filTErs oR other correlation receiVer meThODs or OThEr optImum recEIvER MetHoDs, DepEnDInG on thE trAnsmittEd signals. OTheR mEthods such as ENeRgy detectoRs (e.G., radiometers) WitH or witHoUt tRAckinG maY also Be used, HOwever, They will gIvE Less opTImal resULTs, BecaUse of practical limITaTIons on input banD-pass fIlTEr DESigNs.
IT should be uNdErstoOD that usINg A PLUraLIty of correlatIon receiverS For The samE sLot MAy incrEase tHe FAlsE alarm probaBiliTy and hencE the thREshold fOR positiVe deteCtiOn mAy be ADjUsTed To PRovIDe A deSIreD low falsE aLaRm proBabiLITY.
the sYstEm maY also Be provided witH a dIsplAY 110 foR dispLayinG the DaTa, and With a uSer inTeRface 112 which is useD by aN operator To cOnTroL bOth thE OperatIon Of tHe systeM. The useR IntErFACE aLso preferably contrOlS THe Display aNd the mEMoRy TO allow foR tHe oPeraTOR to reView THe Maps prevIously GEnErAted or tO gEneratEd New DisPlays BAsed On infoRmation pRevioUSly received.
ThiS System works weLL. HOWEvER, theRe iS a need for imProvED accUracY Of MapPIng anD/or utIlIZiNG a relatively small peRcEntage Of parTicipating vehIcles.
The prESENt inventIon pROvIDes a system and mEthod For mapping PArameterS of a tRaffic coNgestion, e.G., A Road congEstIon, RelAtiVE To A focus. Mapping OF The rOaD congesTioN may incLudE deTerMinAtIon of an avErage lenGtH oF tHe RoaD congEStion oveR a TimE iNteRval, mOTion raTe in tHe roAd CoNGesTion and ARrIVAl raTe To The rOad CoNgestIon. THEse ParametErs, in turn, May BE useD tO dEterminE an expected deLaY in traveliNg ThrOughouT THe road coNgestion as well as trends (i.E., Changes WitH time) In thE road congEstIon.
The MapPIng is pErformEd relAtIve TO A mappING fOcuS, tYpically thE FRonT end oF a Road CongestIon. The mapping focus IS prEferably identIfiEd usING tHe sYStEM anD mEThoD DEscribed in the abOve-mentionEd pcT publicatioN wO 96/14586, oR iT may be iDentifiEd usiNG any othEr suitablE method knOwN in tHE Art, For example, By simple Polling of PRedesIGnAted tArgEt vehiClEs. ALternAtivelY, The MappiNg focuS mAy be prOvideD fRom an extErnal source, for example, baSed on rEportS reGarding a pRobLEmaTic intersEctiOn or suspecT inTerSectiOns THat arE to bE CoNtiNUouslY monITored.
In an EMbOdiMENt Of the presenT INVenTion, tHe mAPping sYsteM constructs snapshOTs of mapping samPles RECeiVed FRom a SmAll percentage oF prEdESIgnated pRoBes, e.g., a small PercentaGe OF vehiCles eqUipped With an aPPRoPRiate rEceiVer And transmIttEr. tHe mappiNg SaMPles arE preFeRably rEceiveD In reSPOnse to predefined BroadCASt queRIes Sent fRoM the mapPIng sYstem. In an eMbodiment of The invEntiOn, the DetermiNaTion of The
 also be implemented, forexample, u singset  of  D FT"" s or  an FFT (for C W  sig nals), matched filters  or o th e r co r re latio n recei v er m eth od sorot h er  opti mum  receiv er methods , d ep ending on th e  t ransmitted  si gnals. Other  me thodssu cha s ene rgy  dete ctors( e.g.,radiomete rs )  witho r witho u t  t rack ing may also be u s ed ,  however, they  willgi v el e ssopt imal resul ts , bec a use ofp ra c t i cal limitations o n input ban d -pa ss fil te r d e signs. 
It s ho u ldbe understo od t hat using  a plu r ality o f  correl ationrec eiv ersf or  t hesa m e s l ot  ma y  in crease t he  f alsealar m p r obab ili ty a nd he nce the thres hol d fo r  po sitiv e det ecti on  maybe adj usted  t o provide a des ired  low fals e a la rmpr obabi l ity.
T hesys tem may  also b e  pr ov i d e dwith a display 110  f o r  d isplayin g thed at a, and with  a  us er i n t erfac e 11 2  w hich isused b y  a noperato rto con tr olbot h the oper ationof the s ystem .  The user inte r face also pre f er a b ly cont rol s the displ ay a n d th e me m or y t o  allo w for  t h eo perator to review t he  mapsprevi ously generat ed or to g e n e rated ne w di s pl a ys based on in forma tion previ o usly rec eived .
This s ystem wor k s  well. H owe ver , t her e is  a need for i m p rove daccurac y o f mappi ngand /or  ut il izing a r elativel ysm al lper centa g e of par ti cip at ing  vehi c les.
T he pr esen tin v ent ion pro v id e s  a s ys te m an d m et hod f or m a ppi ng para meters of  at raff ic  c ongesti on, e.g., a r oa d congesti on , r elativ e to a foc us. Mapping of the road congest ion  mayincl ude deter min ationofa n aver age le ngthof  th e roadc o ng est io n over a t i m e i nterv al , mo tion ra te in the road con g est ion and arriv alrate t othe ro a d c on g est i o n. These parame ters, in t ur n ,may be use d  to  d etermin e an ex pecte d  delayin travel ing throu gh outt h e r oad conges tion aswell as t r ends( i. e., c han ges wi th  ti me) i n ther oad  cong estion .The ma pping  i s perfor med relative to a mappi ng foc us, t ypi cally the  fr o ntend of aroad  congestio n.The  mapp ing focus  isp re fer a bly i dent i fied usin g  t hes y st em and meth o d des cribe d i n  the a bove -mentioned PCT Pu b lication WO 96 /145 8 6 , o r i t  may  b e identified u sin ga n y othersu itable meth od known  i n  theart, f or exa mple, b y si m ple po llin g o f predesi gna te d  target  v eh i cles.Alte rn ativel y, the mapp i n g focus may be p rovid e d  from anexter na l sourc e , fo r example,  based on r eports  reg ardin g a pro bl ematic  in te rsection o r  suspectinter section sthat  ar e to b e co n t inuou slymo nit ored.
Ina n  e m bo di m ent  ofthe p re sent  inventio n , the ma ppi n g syste mcon s t ructss na p s hots of ma ppi ng sa m p les receiv e d fr o ma  smal l perc entage  of pre d esi gn ated pr obe s ,  e.g., asmall per c ent ag e of  vehicle sequi pp edwi th an appropria te recei ver andt r ansmit ter .  The mappin gsamples areprefe ra b ly rece i v edin resp o nse  to  pr edef ine d br o adcast queries sent from  the  mapp i ngsyste m. In  a n embodi m entof the i n vention, thedetermination o f  th e 
 also_be implemented,_for example, using set_of DFT""s_or_an FFT_(for_CW signals), matched_filters or other_correlation receiver methods or_other optimum receiver_methods,_depending on the transmitted signals. Other methods such as energy detectors (e.g., radiometers) with_or_without tracking_may_also_be used, however, they will_give less optimal results, because_of practical_limitations on input band-pass filter designs.
It should be_understood_that using a_plurality of correlation receivers for the same slot may_increase the false alarm probability and_hence the threshold_for_positive_detection may be adjusted_to provide a desired low false_alarm probability.
The system may also be_provided with a display 110 for displaying_the data, and with a user_interface 112 which is used_by an_operator to control both the_operation of the_system. The_user interface also_preferably controls the display and the_memory to allow_for the operator to review the_maps_previously generated or_to_generated_new displays_based on information_previously_received.
This system_works_well. However, there is a need_for_improved accuracy of mapping and/or utilizing a_relatively small percentage of_participating_vehicles.
The present invention provides_a system and method for_mapping parameters of a traffic congestion,_e.g., a_road congestion,_relative to a focus. Mapping of the road congestion may include_determination of an average length of_the road congestion over_a time_interval,_motion rate in_the_road congestion_and arrival rate to the road congestion._These parameters,_in turn, may be used to_determine an expected delay_in_traveling throughout the road congestion as_well as trends (i.e., changes with_time) in the road congestion.
The_mapping_is_performed relative to a mapping_focus, typically the front end of_a road congestion._The mapping focus is preferably identified using_the_system and method described in the_above-mentioned_PCT Publication WO 96/14586, or it_may_be_identified using any other suitable_method known in the art, for_example, by simple polling of predesignated target vehicles. Alternatively,_the mapping focus_may be provided from an_external_source,_for example, based on reports regarding a problematic intersection or_suspect intersections_that are to_be continuously monitored.
In an embodiment of the present invention, the_mapping system constructs snapshots of mapping samples_received from a small percentage of predesignated probes, e.g., a small_percentage of vehicles equipped with an appropriate receiver_and transmitter. The mapping samples are preferably_received in response to_predefined_broadcast queries sent from the mapping system._In_an_embodiment_of the invention,_the determination of_the