{"title":"Estimation of traffic variables using a linear model of traffic flow","authors":"Dipankar Ghosh, C.H. Knapp","doi":"10.1016/0041-1647(78)90027-8","DOIUrl":"10.1016/0041-1647(78)90027-8","url":null,"abstract":"<div><p>Estimation of traffic velocity and the number of vehicles on adjacent sections of a limited access highway is examined. The method evaluated is based upon application of Kalman Filtering Methods to a linear state variable model of traffic flow. The estimator utilizes velocity and flow measurements at selected points along the highway. The flow measurement is a nonlinear function of the state variables and necessitates linearization about the one step ahead prediction of the state (extended Kalman Filter) or about nominal values of the state variables. It is shown that performance using Lincoln Tunnel data is comparable in either case to that of methods previously reported and provides a substantial savings in storage requirements. Also demonstrated is the fact that flow at an internal measurement point may be deleted from the observation vector without a serious effect on performance. This would arise, for example, if control of traffic were to be exercised at such a point.</p></div>","PeriodicalId":101259,"journal":{"name":"Transportation Research","volume":"12 6","pages":"Pages 395-402"},"PeriodicalIF":0.0,"publicationDate":"1978-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0041-1647(78)90027-8","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80521855","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Statistics of delay for a driver population with step and distributed gap acceptance functions","authors":"Dennis E. Blumenfeld, George H. Weiss","doi":"10.1016/0041-1647(78)90031-X","DOIUrl":"10.1016/0041-1647(78)90031-X","url":null,"abstract":"<div><p>A model generally used for the reduction of gap acceptance data is one in which each driver has a unit step gap acceptance function, but the time of the step is distributed over the driver population. Data is now available to show that individual gap acceptance functions do not take the form of a step. In this investigation we assume that the individual gap acceptance function takes the form <span><span><span><math><mtext>α(t)</mtext><mtext>= 0</mtext><mtext>t ⩽ T</mtext><mtext>= 1 − exp [−β(t−T)</mtext><mtext>t ⩾ T</mtext></math></span></span></span> but the data customarily available is reduced as if they came from a distribution of step functions. Under these circumstances we show that for a single car waiting time problem, the mean delay is calculated correctly using either assumption of the individual gap acceptance functions. The variance of the calculated waiting time would be overestimated as would be the probability of zero delay. The capacity would be overestimated. Data available from measurements by Bottom and Ashworth suggest that the discrepancies caused by assuming step gap acceptance functions may not be too large.</p></div>","PeriodicalId":101259,"journal":{"name":"Transportation Research","volume":"12 6","pages":"Pages 423-429"},"PeriodicalIF":0.0,"publicationDate":"1978-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0041-1647(78)90031-X","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77473430","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Path analysis: Its use in transportation research","authors":"Peter Gilmour","doi":"10.1016/0041-1647(78)90025-4","DOIUrl":"10.1016/0041-1647(78)90025-4","url":null,"abstract":"<div><p>Sometimes a transportation researcher is confronted with a problem which can be represented by a set of variables which are causally related through time. One approach to studying such a problem is to use path analysis to formulate and test models of the variable set.</p><p>This paper describes the basic method of path analysis and its use as a tool to aid airline carriers in capital equipment acquisition decisions. In addition to this application of path analysis, some other uses of this methodology in other transportation-related areas are discussed.</p></div>","PeriodicalId":101259,"journal":{"name":"Transportation Research","volume":"12 6","pages":"Pages 377-384"},"PeriodicalIF":0.0,"publicationDate":"1978-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0041-1647(78)90025-4","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72764441","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"An analysis of road expenditures and payments by vehicle class","authors":"","doi":"10.1016/0041-1647(78)90039-4","DOIUrl":"10.1016/0041-1647(78)90039-4","url":null,"abstract":"","PeriodicalId":101259,"journal":{"name":"Transportation Research","volume":"12 6","pages":"Page 435"},"PeriodicalIF":0.0,"publicationDate":"1978-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0041-1647(78)90039-4","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"100723815","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Transportation systems evaluation","authors":"Terry L. Friesz","doi":"10.1016/0041-1647(78)90033-3","DOIUrl":"10.1016/0041-1647(78)90033-3","url":null,"abstract":"","PeriodicalId":101259,"journal":{"name":"Transportation Research","volume":"12 6","pages":"Page 432"},"PeriodicalIF":0.0,"publicationDate":"1978-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0041-1647(78)90033-3","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86105972","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Review and compilation of demand forecasting experiences: An aggregation of estimation procedures","authors":"Christopher Hendrickson","doi":"10.1016/0041-1647(78)90034-5","DOIUrl":"10.1016/0041-1647(78)90034-5","url":null,"abstract":"","PeriodicalId":101259,"journal":{"name":"Transportation Research","volume":"12 6","pages":"Pages 432-434"},"PeriodicalIF":0.0,"publicationDate":"1978-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0041-1647(78)90034-5","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84333534","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}