00939817

Component

This paper outlines a quasi-dynamic traffic assignment algorithm for practitioners that realistically limits link flows to capacity during relatively short assignment periods. This aspect of the model is a substantial improvement over conventional static traffic assignment methods typically used by metropolitan planning organizations, which frequently estimate link flows greater than practical link capacities. The quasi-dynamic assignment algorithm considers the effects of queued vehicles at bottlenecks and intersections. It can also model short term peaking of traffic and brief reductions in link capacities caused by traffic incidents. The algorithm's dynamic nature makes it a more appropriate tool than static traffic assignment for evaluating many intelligent transportation system strategies to reduce highway congestion. The algorithm uses advanced traffic assignment features in a commercially available transportation planning software package, existing coded highway networks and trip tables. Twenty-four hour traffic estimates are constructed from assignments for ninety-six fifteen-minute periods. The algorithm iterates through eight sets of traffic assignments in a fifteen-minute period, estimating the contribution of traffic originating in the fifteen minutes to current period link flows, as well as the link flows in the following seven fifteen-minute periods. Queues form on links when assigned traffic exceeds capacity, and any queues remaining at the end of an assignment period are carried over to the following period. Intersection approach capacities are also adjusted by fifteen-minute period. Two case studies - a freeway bottleneck and a saturated intersection between suburban arterial streets - illustrate the detailed traffic forecasts provided by the algorithm.

The CD-ROM contains the proceedings of the sixth, seventh and eighth conferences. The eighth conference proceedings were published in October 2001.

English

p. 339-348

2002

Eighth TRB Conference on the Application of Transportation Planning Methods

Figures (5) ; References (8) ; Tables (2)

Algorithms; Bottlenecks; Case studies; Dynamic traffic assignment; Highway capacity; Intersections; Traffic flow; Traffic forecasting; Traffic incidents; Traffic queuing; Transportation planning

Highways; Planning and Forecasting; I72: Traffic and Transport Planning

TRIS, TRB

Mar 21 2003 12:00AM

• A BEST PRACTICE TRUCK FLOW ESTIMATION MODEL FOR THE NEW YORK CITY REGION
• ADDRESSING ENVIRONMENTAL JUSTICE (EJ) THROUGH COMMUNITY IMPACT ASSESSMENT (CIA)
• AN ANALYSIS OF TRAFFIC GROWTH RATES ON THE TEXAS-MEXICO BORDER
• B-NODE MODEL: NEW SUBAREA TRAFFIC ASSIGNMENT MODEL & APPLICATION
• CONGESTION PRICING AND ROADSPACE RATIONING: AN APPLICATION TO THE SAN FRANCISCO BAY BRIDGE CORRIDOR
• CORRIDOR SIMULATION STUDY FOR THE BRIDGE OF AMERICAS, EL PASO, TEXAS
• DEVELOPMENT OF AN ENVIRONMENTAL JUSTICE ANALYSIS METHODOLOGY FOR GEORGIA DEPARTMENT OF TRANSPORTATION'S MULTIMODAL TRANSPORTATION PLANNING TOOL
• ECONOMIC IMPACTS OF RAISED MEDIANS IN TEXAS: METHODOLOGY AND CASE STUDY RESULTS
• ENHANCING PUBLIC INVOLVEMENT THROUGH THE FULL UTILIZATION OF COMMUNICATIONS TECHNOLOGY
• FINANCING THE REGIONAL TRANSPORTATION PLAN: BALANCING EXPECTATIONS WITH FISCAL CONSTRAINT
• FLEXIBLE FUNDING: TRENDS AND POSSIBILITIES
• FLORIDA URBAN LAND USE ALLOCATION MODEL (ULAM)
• GIS APPLICATIONS USING DIGITAL ORTHOPHOTO DATA
• HIGHWAY ECONOMIC REQUIREMENTS SYSTEM FOR INDIANA: STATEWIDE PLANNING APPLICATIONS
• IMPLEMENTING THE LAND USE AND TRANSPORTATION POLICY IN OREGON'S 1999 HIGHWAY PLAN
• IMPROVED PLANNING DATA COLLECTION USING HANDHELD COMPUTERS
• LAND DEVELOPMENT AND ACCESS MANAGEMENT STRATEGIES FOR INTERCHANGE AREAS
• LESSONS LEARNED: ACCESS MANAGEMENT PROGRAMS IN SELECTED STATES
• MAKING LIFE EASIER FOR PLANNERS, ELECTED OFFICIALS, AND THEIR CONSTITUENTS: VISUALIZING THE INTERACTION OF TRANSPORTATION AND LAND USE
• MODIFICATIONS TO TRADITIONAL EXTERNAL TRIP MODELS
• ORIGIN AND DESTINATION ESTIMATION IN NEW YORK CITY USING AUTOMATED FARE SYSTEM DATA
• PROCEEDINGS OF THE EIGHTH TRB CONFERENCE ON THE APPLICATION OF TRANSPORTATION PLANNING METHODS, CORPUS CHRISTI, APRIL 22-26, 2001
• PROVIDING PUBLIC ACCESS TO TRANSPORTATION PROJECTS AND FUNDING WITH A VISUAL, INTERACTIVE TRANSPORTATION IMPROVEMENT PROGRAM
• PUBLIC INVOLVEMENT PLAN FOR THE KELLY PARKWAY CORRIDOR STUDY
• PUBLIC INVOLVEMENT: "DO YOU HAVE A 'POLICY' OR A 'PLAN'?"
• QUICKRIDE: THE KATY HOT LANE PROJECT IN HOUSTON
• RECENT EXPERIENCE WITH TIME OF DAY MODELING
• RECOMMENDED GUIDELINES FOR THE CALIBRATION AND VALIDATION OF TRAFFIC SIMULATION MODELS
• STATEWIDE PLANNING TOOL TO SUPPORT MULTIMODAL DECISION-MAKING
• SUBURBAN FIXED RAIL TRANSIT PLANNING IN NORTHERN VIRGINIA
• SURVEY DATA REPAIR USING HOT-DECK IMPUTATION PROCEDURE
• TCSP: DEVELOPING INNOVATIVE COMMUNITY BASED PLANNING TOOLS
• THE NORTHWEST ARKANSAS TRANSIT ASSESSMENT STUDY
• THE ROLE OF FIXED COMMITMENTS IN SHAPING ACTIVITY-TRAVEL PATTERNS
• THE TRIUMPH OF THE TRIVIAL MPO
• TRAFFIC FORECASTING TOOL (TFT): A GIS-BASED FORECASTING APPLICATION FOR THE INDIANA DEPARTMENT OF TRANSPORTATION
• TRANSPORTATION DECISION MAKING PROCESS
• TRAVEL DEMAND MODELING AND CONFORMITY DETERMINATION: THE ATLANTA REGIONAL COMMISSION CASE STUDY
• USING A TRADITIONAL TRAVEL DEMAND FORECASTING MODEL TO PERFORM VARIABLE PRICING ANALYSIS
• USING TRANSIMS IN TRANSPORTATION DECISION MAKING
• VALUE PRICING PROJECTS AROUND THE UNITED STATES