Modeling

Review of “Bay Area/California High-Speed Rail Ridership and Revenue Forecasting Study”

Brownstone, David
Hansen, Mark
Madanat, Samer
2010

We have reviewed the key components of the California High Speed Rail Ridership Studies. The primary contractor for these studies, Cambridge Systematics (CS), has followed generally accepted professional standards in carrying out the demand modeling and analysis. Nevertheless we have found some significant problems that render the key demand forecasting models unreliable for policy analysis. This Executive Summary describes the most serious problems. The body of this report elaborates on these problems and describes additional concerns we have. In broad terms, the approach taken by CS...

Genearating Probabilistic Capacity Profiles from weather forecast: A design-of-experiment approach

Buxi, Gurkaran
Hansen, Mark
2011

It is common understanding that weather plays an important role in determining the capacity of an airport. Severe weather causes capacity reductions, creating a capacity demand imbalance, leading to delays. The role of air traffic flow management (ATFM) measures is to reduce these delay costs by aligning the demand with the capacity. Ground delay program (GDP) is one such measure. Though the GDP is initiated in poor weather conditions, and weather forecasts are subject to errors, present GDP planning procedures are essentially deterministic in nature. Forecast weather is translated into...

Induced Travel Demand and Induced Road Investment: A Simultaneous Equation Analysis

Cervero, Robert
Hansen, Mark
2002

This paper presents simultaneous models that predict induced travel demand and induced road investment using an array of instrument variables reflecting political, environmental, and demographic influences. From a panel data set consisting of 22 years of observations for 34 California urban counties, short-run elasticities are estimated. Both the Vehicle– Miles-Travelled model and the Lane–Miles model feature good statistical fits and highly significant parameter estimates. While the research found strong reciprocal relationships between road investment and travel demand, the elasticity...

Longitudinal Control of Heavy Duty Vehicles: Experimental Evaluation

Yanakiev, Diana
Eyre, Jennifer
Kanellakopoulos, Ioannis
1998

This report describes the results of experimental evaluation of longitudinal control algorithms for commercial heavy vehicles (CHVs). Given the problem of delays in the fuel and brake actuators of automated CHVs, the researchers present improved modeling of air brakes for CHVs, and novel nonlinear algorithms for the longitudinal control of CHVs without intervehicle communication. The significance of these results in terms of Intelligent Transportation Systems (ITS) deployment is that one of the major obstacles to autonomous vehicle following for CHVs has now been removed The authors also...

Deep Learning Framework for Vessel Trajectory Prediction using Auxiliary Tasks and Convolutional Networks

Shin, Yuyol
Kim, Namwoo
Lee, Hyeyeong
In, Soh Young
Hansen, Mark
Yoon, Yoonjin
2024

With the exponential growth in vessel traffic and the increasing complexity of maritime operations, there is a pressing need for reliable and efficient methods to forecast vessel movements. The accurate prediction of vessel trajectories plays a pivotal role in various maritime applications, including route planning, collision avoidance, and maritime traffic management. Traditional statistical and machine learning approaches have shown limitations in capturing the complex spatial–temporal patterns of vessel movements. Deep learning techniques have emerged as a promising solution due to...

Scenario-Free Sequential Decision Model for the Single Airport Ground Holding Problem

Liu, Pei-Chen Barry
Hansen, Mark
2007

This paper aims to advance the support of decision-making in air traffic flow management under uncertainty with a focus on the single airport ground holding problem (SAGHP). Learning from the shortcomings of the scenario-based models for SAGHP, which address uncertainty using probabilistic capacity scenarios, the paper develops a sequential decision model that is not limited by a small set of scenarios. The paper presents computational strategies and demonstrates the computational feasibility of the model.

Improvements to Airport Ground Access and Behavior of Multiple Airport System: BART Extension to San Francisco International Airport

Monteiro, Ana Beatriz Figueiredo
Hansen, Mark
1996

Metropolitan regions with more than one major airport—multiple airport systems (MASs)—are important to the U.S. air transport system because of the large number of passengers they serve. Airport ground access factors strongly influence the allocation of traffic in MASs. The effects of improvements to airport ground access (by nonautomobile modes) on airport use in a MAS are analyzed. A case study of an extension of a Bay Area Rapid Transit rail link into the San Francisco International Airport (SFO) is presented. Two airport choice models were developed. One is a nested logit model in...

Optimal Detector Location for Bus Signal Priority

Liu, Huitao
Skabardonis, A
Zhang, Wenfen
Li, Mei
Transportation Research Board
2004

A theoretical model is presented to quantitatively address the relation between bus detector location and effectiveness of transit signal priority (TSP) systems, supplemented by a sample model application and simulation experiments on a real-world arterial corridor. The simulation results agree very well with results from the theoretical model. The findings of this research contribute to a better understanding of the interaction of the various components of TSP systems, which can lead to better TSP design and implementation.

Progression Through a Series of Intersections with Traffic Actuated Controllers. Volume 1: Technical Report. Final Report

Skabardonis, A
Deakin, Harvey, Skabardonis, Incorporated
Federal Highway Administration
1988

Many traffic control systems on urban arterials and grid networks include signals with actuated controllers. However, commonly used computer programs for signal timing cannot directly optimize the timing of coordinated signals. Users have to apply techniques designed for pretimed signals, and then "translate" the optimized pretimed settings into settings for the actuated controllers. In addition, other signal control choices, such as whether to operate a particular signal as pretimed, semi-actuated, or fully actuated, are left entirely to the user. This report describes the development of...

Proof of Concept for the Trajectory-Level Validation Framework for Traffic Simulation Models

Xyntarakis, Michalis
Alexiadis, Vassili
Punzo, Vincenzo
Campbell, Robert
Skabardonis, Alex
Flanigan, Erin
Cambridge Systematics
Purdue University
Indiana Department of Transportation
Federal Highway Administration
Department of Transportation
2017

Based on current practices, traffic simulation models are calibrated and validated using macroscopic measures such as 15-minute averages of traffic counts or average point-to-point travel times. For an emerging number of applications, including connected vehicles, the realism of simulated driver dynamics at the second-by-second or subsecond trajectory level plays an important role. This report presents a Proof of Concept Application (PCA) for the Trajectory Level Validation Framework, which is presented in a separate report. The structure of this document parallels that of the Validation...