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The use of dummy variables in trip generation analysis
Translated abstracts of papers KENNETH W HEATHINGTONand EDWARDI~UIOR The use of dummy varnables UI trap generation analysts Transpn Res 6, 131-142.
In many mstances of model formulatton, approxunatloas are made for slmphclty m computatton. Most often the assumptions are made with a knowledge of probable dtscrepancy. However, tt w not always a pro5toble trade-off that results m substltutmg slmpltctty for complextty. Particularly IS this true when usmg hnear regmss~oa techmquea. R-on analysts IS used exttnavely m the transportation plannmg area, perhaps, beca~ of Its stmpltctty of comprehenston and computatloa. Methodology in thts presentation haa been revlowed for treatment of (1) non-lmear and (2) discrete relattonshlps III lmear regressIon analysa. Thu methodology has duect apphcatlon to tnp genentton analyas used in urban transportatton plannmg The techmque of dummy vanabks IS explored tn great detad. A denvatlon of the mathematical relattonshlps which lead to the model formulatron 18made When probkms of non-hneanty and category type vanables do not exist, tt IS not recommended that the dummy vanable tecluuque be used. The dummy vanable technrque IS stmply a tool to rud the analyst m model buddmg. Thus techmque, hke most others, has both advantages and disadvantages It does seem to atd m the mterpretauon of more complex non-lmear and category type vanables In many cases a more dear and conctse analysts can be made usmg the dummy vanable techmque than m the transgeneratton of the mdependent vanabla The part~ular approach to the use of dummy variables taken m thrs presentatton represents only one of several approaches. Those usmg the dummy vanable techmque m tnp generatIon analysis should be farmbar wtth the problems mherent m model development. Inexpcnenced personnel applymg this techmque wdl often find that It can lead to erroneous results
S. H STARRand B M. HOROWITZ’A control theoretic approach to the analysrs and desrgn of vehwdar cotmoys Transpn Res 6, 143-M. In many arw of transportation anaiys~s one IS interested tn a group of vehicles which are
proceedmg along a common route (I e. a convoy) TIus paper presents (1) a set of heurtsttc de6mtlons whh attempt to charactenze merent typea of convoys, (2) a mathemattcal fornudatton of the convoy problem whtch complements the detimttons. (3) a general algonthmtc solution to a class of convoy problems and (4) two spcc& examples. The methodology which IS presented IS useful for analyztng or destgnmg a non-stationary convoy, pcxturbed by stochastic forcea and subJect to Internal and external detemumsta forces.
ROBERTG. STEQANEK. Norwork rmplrcatrons OR control system design for a dual-mode transportation system. Transpn Res. 6. 157-167 Important system problems associated mth the operatton of an automated hlghway network are exammed under the assumptron that the synchronous movmg cell control scheme IS the basts for m&ndual vehicle control. The fundamentals of a network traffic management strategy are dtscussed and Important constramts that are unposed on control system design by such a strategy are stated The paper mlcates the dependence of effecttve network capacity on the rules of the traffic management strategy, on the design of mterchanges for automated tughways, and on velucle performance and passenger comfort constderatlons. A hstmg of Important research questIons associated with automated hlghway network operatmg strategy and control system design IS also glvcn IV
In many mstances of model formulatton, approxunatloas are made for slmphclty m computatton. Most often the assumptions are made with a knowledge of probable dtscrepancy. However, tt w not always a pro5toble trade-off that results m substltutmg slmpltctty for complextty. Particularly IS this true when usmg hnear regmss~oa techmquea. R-on analysts IS used exttnavely m the transportation plannmg area, perhaps, beca~ of Its stmpltctty of comprehenston and computatloa. Methodology in thts presentation haa been revlowed for treatment of (1) non-lmear and (2) discrete relattonshlps III lmear regressIon analysa. Thu methodology has duect apphcatlon to tnp genentton analyas used in urban transportatton plannmg The techmque of dummy vanabks IS explored tn great detad. A denvatlon of the mathematical relattonshlps which lead to the model formulatron 18made When probkms of non-hneanty and category type vanables do not exist, tt IS not recommended that the dummy vanable tecluuque be used. The dummy vanable technrque IS stmply a tool to rud the analyst m model buddmg. Thus techmque, hke most others, has both advantages and disadvantages It does seem to atd m the mterpretauon of more complex non-lmear and category type vanables In many cases a more dear and conctse analysts can be made usmg the dummy vanable techmque than m the transgeneratton of the mdependent vanabla The part~ular approach to the use of dummy variables taken m thrs presentatton represents only one of several approaches. Those usmg the dummy vanable techmque m tnp generatIon analysis should be farmbar wtth the problems mherent m model development. Inexpcnenced personnel applymg this techmque wdl often find that It can lead to erroneous results
S. H STARRand B M. HOROWITZ’A control theoretic approach to the analysrs and desrgn of vehwdar cotmoys Transpn Res 6, 143-M. In many arw of transportation anaiys~s one IS interested tn a group of vehicles which are
proceedmg along a common route (I e. a convoy) TIus paper presents (1) a set of heurtsttc de6mtlons whh attempt to charactenze merent typea of convoys, (2) a mathemattcal fornudatton of the convoy problem whtch complements the detimttons. (3) a general algonthmtc solution to a class of convoy problems and (4) two spcc& examples. The methodology which IS presented IS useful for analyztng or destgnmg a non-stationary convoy, pcxturbed by stochastic forcea and subJect to Internal and external detemumsta forces.
ROBERTG. STEQANEK. Norwork rmplrcatrons OR control system design for a dual-mode transportation system. Transpn Res. 6. 157-167 Important system problems associated mth the operatton of an automated hlghway network are exammed under the assumptron that the synchronous movmg cell control scheme IS the basts for m&ndual vehicle control. The fundamentals of a network traffic management strategy are dtscussed and Important constramts that are unposed on control system design by such a strategy are stated The paper mlcates the dependence of effecttve network capacity on the rules of the traffic management strategy, on the design of mterchanges for automated tughways, and on velucle performance and passenger comfort constderatlons. A hstmg of Important research questIons associated with automated hlghway network operatmg strategy and control system design IS also glvcn IV