S.Travis Waller receives Hojjat Adeli Award for Innovation in Computing
The Computer-Aided Civil and Infrastructure Engineering August 2012 special issue on Transportation Engineering includes an announcement that Dr. S. Travis Waller is the recipient of the 2011 Hojjat Adeli Award for Innovation in Computing. This award is based on research published in the journal during his time as Adjunct Professor at The University of Texas at Austin. According to the announcement, the Innovation in Computing award is “awarded annually to the most innovative paper published in the previous volume/year OR the most innovative single author, normally someone who has published more than one paper in the previous three years.”
The articles cited in this award are:
- Duthie, J. C., Unnikrishnan, A. and Waller, S. T. (2011), Influence of Demand Uncertainty and Correlations on Traffic Predictions and Decisions. Computer-Aided Civil and Infrastructure Engineering, 26: 16–29. doi: 10.1111/j.1467-8667.2009.00637.x
This article seeks to address this issue by presenting a new method for evaluating future travel demand uncertainty and finding an efficient technique for generating multiple realizations of demand. The proposed method employs Hypersphere Decomposition, Cholesky Decomposition, and user equilibrium traffic assignment.
- Lin, D.-Y., Valsaraj, V. and Waller, S. T. (2011), A Dantzig-Wolfe Decomposition-Based Heuristic for Off-line Capacity Calibration of Dynamic Traffic Assignment. Computer-Aided Civil and Infrastructure Engineering, 26: 1–15. doi: 10.1111/j.1467-8667.2009.00635.x
Though it is imperative to calibrate the [Dynamic traffic assignment] DTA model such that it can accurately reproduce field observations and avoid erroneous flow predictions when evaluating traffic management strategies, DTA calibration is an onerous task due to the large number of variables that can be modified and the intensive computational resources required. To compliment other research on behavioral and trip table issues, this work focuses on DTA capacity calibration and presents an efficient Dantzig-Wolfe decomposition-based heuristic that decomposes the problem into a restricted master problem and a series of pricing problems.
- Ng, M., Park, J. and Waller, S. T. (2010), A Hybrid Bilevel Model for the Optimal Shelter Assignment in Emergency Evacuations. Computer-Aided Civil and Infrastructure Engineering, 25: 547–556. doi: 10.1111/j.1467-8667.2010.00669.x
The rise in natural and man-made disasters in recent years has led to an increased interest in emergency evacuation planning. Athough the vast majority of the existing evacuation planning models assumes system optimal (cooperative) behavior, recent research has shown that during large evacuations people tend to exhibit selfish (noncooperative) behavior. This article presents a hybrid bilevel model that balances both behavioral assumptions (in the upper level, shelter assignment occurs in a system optimal fashion, whereas evacuees are free to choose how to reach their assigned shelters in the lower level), hence providing a model that is more in line with the current state-of-the-knowledge of human behavior during disasters.
- Ng, M., Lin, D. Y. and Waller, S. T. (2009), Optimal Long-Term Infrastructure Maintenance Planning Accounting for Traffic Dynamics. Computer-Aided Civil and Infrastructure Engineering, 24: 459–469. doi: 10.1111/j.1467-8667.2009.00606.x
Periodic infrastructure maintenance is crucial for a safe and efficient transportation system. Numerous decision models for the maintenance planning problem have been proposed in the literature. However, to the best of our knowledge, no model exists that simultaneously accounts for traffic dynamics and is intended for long-term planning purposes. This article addresses this gap in the literature. A mixed-integer bi-level program is introduced that minimizes the long-term maintenance cost as well as the total system travel time.
- Unnikrishnan, A., Valsaraj, V., Damnjanovic, I. and Waller, S. T. (2009), Design and Management Strategies for Mixed Public Private Transportation Networks: A Meta-Heuristic Approach. Computer-Aided Civil and Infrastructure Engineering, 24: 266–279. doi: 10.1111/j.1467-8667.2008.00587.x
This article presents a new multi-objective mathematical programming framework to model interactions between public and private sector in constructing and maintaining highway networks using the build, operate, and transfer scheme. In this study, private companies are assumed to have a degree of control over highway sections on which they perform maintenance and rehabilitation and capacity expansion activities. The private investors recover the cost of construction by levying tolls. The public agency is assumed to maintain the rest of the network with the objective of minimizing total system generalized cost. The bi-directional impact of roadway utilization on deterioration and deterioration on utilization is modeled in this study. The model accounts for route choice of users and all users are assumed to choose routes that have equal and minimal experienced generalized cost.
We extend our congratulations to Dr.Waller. Dr. Waller recently left The University of Texas at Austin for a position at the University of New South Wales where he serves as the Evans & Peck Professor of Transport Innovation and Director of the Research Centre for Integrated Transport Innovation (rCITI). While at UT Austin, he was also instrumental in the development of the Network Modeling Center (Director, Jen Duthie) and the Electric Vehicle Transportation and Electricity Convergence (EV-TEC) Center (Director, Ross Baldick).