Travel Behavior

Travinfo Field Operational Test: Work Plan For The Target, Network, And Value Added Reseller ( V A R ) Customer Studies

Yim, Y. B.
Hall, Randoph
Skabardonis, Alex
Tam, Robert
Weissenberger, Stein
1997

This report contains detailed work plans for the following evaluation tasks associated with the TravInfo evaluation study. These include: the target, Value Added Reseller (VAR) customer studies, and the network performance evaluation. The target study focuses on a high impact Bay Area corridor to evaluate TravInfo impacts or benefits to Bay Area travelers. The network performance evaluation simulates the road conditions in that corridor to estimate TravInfo impacts at the aggregate level. The VAR customer study provides information on those consumers who actually purchase and use Advanced...

Rethinking the Driver Population Factor: Examination of Freeways in California

Seeherman, Joshua
Skabardonis, Alexander
2013

Freeway analysis procedures in the widely used Highway Capacity Manual (HCM) include the input of a driver population factor (Fp), which allows the analyst to adjust the demand depending on the familiarity of drivers with the roadway. This adjustment is based on the assumption that unfamiliar drivers will drive at slower speeds with longer headways and that higher capacity would therefore be required. However, little research supports the use of the Fp, and the HCM cautions against the use of Fp unless the analyst is fairly certain the traffic stream is actually unfamiliar with the roadway...

A Competitive, Charter Air-service Planning Model for Student Athlete Travel

Gupta, Gautam
Goodchild, Anne
Hansen, Mark
2011

This paper presents a model for planning an air charter service for pre-scheduled group travel. This model is used to investigate the competitiveness of such an enterprise for student athlete travel in conference sports. The relevant demand subset to be served by a limited charter fleet is identified through a comparison with existing scheduled travel options. Further, the routing and scheduling of the charter aircraft is performed within the same framework. Through this modeling a method for formulating and accommodating continuous time windows and competitive market dynamics in strategic...

California’s Freeway Service Patrol Program: FSP Beat Evaluation Model; Methodology and Parameter Estimation (FY 2014-15)

Mauch, Michael
Skabardonis, Alex
University of California, Berkeley
California Department of Transportation
2016

The Freeway Service Patrol (FSP) is an incident management program implemented by Caltrans, the California Highway Patrol and local partner agencies to quickly detect and assist disabled vehicles and reduce non-recurring congestion along the freeway during peak commute hours. The first FSP program was piloted in Los Angeles, and was later expanded to other regions by state legislation in 1991. As of June 2015, there were fourteen participating FSP Programs operating in California, deploying over 340 tow trucks and covering over 1,800 (center-line)miles of congested California freeways. The...

Simple Procedure for Estimating Origin-Destination Matrices for Arterial Corridors

Gomes, Gabriel
Skabardonis, Alexander
Transportation Research Board
2008

This paper will present a four-step framework for computing static origin-destination matrices for linear arterials with intersections. The method allows the user to control the resulting dynamic behavior by adjusting several tunable parameters which relate directly to the turning flows. These parameters include intersection weighting coefficients, which dictate the likelihood that a vehicle traveling along the arterial will turn at each intersection. Six additional parameters are required for each four-branch intersection, giving a total of seven. Three-branch intersections are defined...

Real-Time Monitoring and Control on Signalized Arterials

Skabardonis, Alexander
Geroliminis, Nikolas
2008

An analytical model for real-time estimation of travel times along signalized arterials was developed. The application of the model on two arterial sites and comparisons of the estimated travel times with simulated and field data show that the model accurately predicts travel times on the selected sites. In this article, we present several important extensions and refinements to the model including treatment of long queues and queue spillovers, and algorithms for signal priority to transit vehicles. We also describe the integration of the model into an archival data management system for...

Statistical Characteristics of Transitional Queue Conditions in Signalized Arterials

Vlahogianni, Eleni I
Webber, Charles L
Geroliminis, Nikolas
Skabardonis, Alexander
2007

The performance of signalized arterials is related to queuing phenomena. The paper investigates the effect of transitional traffic flow conditions imposed by the formation and dissipation of queues. A cross-recurrence quantification analysis combined with Bayesian augmented networks are implemented to reveal the prevailing statistical characteristics of the short-term traffic flow patterns under the effect of transitional queue conditions. Results indicate that transitions between free-flow conditions, critical queue conditions that exceed the detector's length, as well as the occurrence...

Reliability Breakpoints on Freeways

Dowling, Richard G
Skabardonis, Alexander
Margiotta, Richard A
Hallenbeck, Mark E
Transportation Research Board
2009

This paper shows through the evaluation of probe vehicle and loop detector data that travel time reliability on a freeway is NOT a function of counted traffic volumes until a “breakpoint volume” is reached. At that breakpoint the travel time reliability decreases (variance increases) abruptly. Once the breakpoint volume is exceeded, the decrease in travel time reliability is so extreme and abrupt as to suggest It is a vertical function, with a non-singular relationship to further volume increases. The breakpoint in reliability generally occurs at a counted volume significantly lower than...

Operation of Traffic Signal Systems in Oversaturated Conditions, Volume 1: Practitioner Guidance

Gettman, Douglas
Abbas, Montasir
Liu, Henry
Skabardonis, Alex
2014

This guide presents a rational approach for identifying traffic control strategies for mitigating oversaturated conditions at signalized intersections. The guide discusses the following components of the rational approach: diagnosis of the type and causes of the oversaturated condition; identification of appropriate operational objective(s) based on the observed condition(s); identification of appropriate strategies to address the situation; and identification of any necessary infrastructure, equipment, or software requirements for each strategy. The intended audience for this guide is a...

Learning the Representation of Surrogate Safety Measures to Identify Traffic Conflict

Lu, Jiajian
Grembek, Offer
Hansen, Mark
2022

Traffic conflict can be identified by the presence of evasive actions or the amount of temporal (spatial) proximity measures like time-to-collision (TTC). However, it is not enough to use only one kind of measures in some scenarios and it is hard to set a threshold for those measures. This paper proposed a method to identify traffic conflict by learning the representation of TTC and driver maneuver profiles with deep unsupervised learning and clustering the representations into traffic conflict and non-conflict clusters. We first trained a transformer encoder to encode sequences of...