Longitudinal and Lateral throughput on an Idealized Highway

Hall, Randolph W.
May 1995
Transportation Science;May95, Vol. 29 Issue 2, p118
Academic Journal
Highway automation has recently enjoyed renewed research interest as a method for solving highway congestion problems. To determine the feasibility of automated highways, it will be essential to estimate the automated highway benefits. A critical task in the analysis of automated highway benefits is to estimate the potential increase in highway capacity. This paper uses deterministic approximations to model highway throughput, accounting for both longitudinal requirements (i.e., lane flow) and lateral requirements (i.e., lane changing). The model also accounts for trip length distributions) and the effect of these distributions on the lane "flux" (i.e., the rate at which vehicles move between adjacent lanes, per unit length of highway). Based on these representations, the model identifies conditions under which lane changes have an appreciable effect on capacity, assuming certain idealized conditions are met. For typical highway parameters (mean trip length of 20 km, and mean speed of 30 m/s), and an increased nominal capacity (i.e., not factoring in lane changes) of 7200 vehicles per hour, the incremental effect of lane changes only appears to be significant (i.e., cause a capacity reduction in excess of 20%) when the time-space requirement exceeds 1000 m-s. As an example, this requirement could imply a lane change maneuver that lasts 10 seconds and requires 100 m of lane-space during execution. This calculation does not factor in queueing effects. To ensure that all or most vehicles succeed in exiting at their desired locations, the actual capacity will have to be decreased somewhat further.


Related Articles

  • On the Flow Capacity of Automated Highways. Bender, J. G.; Fenton, R. E. // Transportation Science;Feb70, Vol. 4 Issue 1, p52 

    Virtually all proposed systems for highway automation have at least one mode in common-steady-state car following. The nature of this mode is extremely important, as it can determine the upper limit of flow capacity of an automated highway. This limit is explored for a linear headway controller,...

  • Everybody wants in -- and out. Wilson, Bill // Roads & Bridges;May2004, Vol. 42 Issue 5, p30 

    Presents information on the construction of a highway to relieve congestion problems in Tampa, Florida. Design of the highway; Reason for choosing Figg Bridge Engineers and contractor PCL Civil Constructors Inc. for the construction of the highway; Details of the construction process.

  • Maine without the pinchers. Hutchins, Benjamin D. // Roads & Bridges;Jun2006, Vol. 44 Issue 6, p86 

    The article focuses on the I-mile Portland Connector highway project in Maine. It is the first project to be undertaken using the design-build process, as opposed to the more traditional design-bid-build process. Shaw Brothers Construction used global positioning system technology to make sure...

  • Automated highway systems. Siuru, Bill // Popular Electronics;Dec98, Vol. 15 Issue 12, p33 

    Focuses on the use of automated highway systems (AHS) as a means of dealing with the expected increase in highway traffic by the year 2020. Objective for the installation of AHS; Overview on the problem of growing urban traffic congestion; Advantages of AHS for highway motorists.

  • Why We Should Care About Traffic. Ewing, Reid // Planning;May2006, Vol. 72 Issue 5, p28 

    The article presents the rationale on why should people care about traffic The author compared the traffic congestion in Florida, where he lives, and Maryland, where he works. He suggested that traffic-responsive systems monitor traffic at key intersections in real time and select the most...

  • State-of-the-art of vehicular traffic flow modelling. Hoogendoorn, S P; Bovy, P H L // Proceedings of the Institution of Mechanical Engineers -- Part I;2001, Vol. 215 Issue 4, p283 

    Nowadays traffic flow and congestion is one of the main societal and economical problems related to transportation in industrialized countries. In this respect, managing traffic in congested networks requires a clear understanding of traffic flow operations; i.e. insights into what causes...

  • Bypass plea for Enniskillen.  // Commercial Motor;4/7/2005, Vol. 201 Issue 5123, p22 

    Reports that businesses could save money a year if a southern bypass was built to ease the congestion problems of the Northern Ireland town of Enniskillen. Route taken by commercial vehicle drivers from west of Ireland to transit the town; Hassle that the current situation causes; Status of the...

  • Keeping Inlets Clean and Green. GOLDBERG, STEVE // Erosion Control;Mar/Apr2013, Vol. 20 Issue 2, p54 

    The article presents information on the construction work of Highway 84, a section of the California State Highway in California. It informs that Alameda County, Livermore in California and California Departmentof Transportation has taken the initiative to monitor the construction work. It also...

  • Highway Infrastructure: Physical Conditions of the Interstate Highway System Have Improved, but Congestion and Other Pressure Continue: GAO-02-1128T. Siggerud, Katherine // GAO Reports;9/26/2002, p1 

    The Interstate Highway System has become central to transportation in the United States. It extends over 46,000 miles in length and includes 210,000 lane miles. The System carries over 24 percent of all vehicle miles traveling in the nation, while making up just 2.5 percent of total lane miles....


Read the Article


Sorry, but this item is not currently available from your library.

Try another library?
Sign out of this library

Other Topics