Saeideh Fallah-Fini

Measuring the efficiency of highway maintenance contracting strategies: A bootstrapped non-parametric meta-frontier approach

Highly deteriorated US road infrastructure, major budgetary restrictions and the significant growth in traffic have led to an emerging need for improving performance of highway maintenance practices. Privatizing some portions of road maintenance operations by state Departments of Transportation (DOTs) under the auspices of performance-based contracts has been one of the innovative initiatives in response to such a need. This paper adapts the non-parametric meta-frontier framework to the two-stage bootstrapping technique to develop an analytical approach for evaluating the relative efficiency of two highway maintenance contracting strategies. The first strategy pertains to the 180 miles of Virginia’s Interstate highways maintained by Virginia DOT using traditional maintenance practices. The second strategy pertains to the 250 miles of Virginia’s Interstate highways maintained via a Public Private Partnership using a performance-based maintenance approach. The meta-frontier approach accounts for the heterogeneity that exists among different types of highway maintenance contracts due to different limitations and regulations. The two-stage bootstrapping technique accounts for the large set of uncontrollable factors that affect the highway deterioration processes. The preliminary findings, based on the historical data for the state of Virginia, suggest that road authorities (counties) that have used traditional contracting for transforming the maintenance expenditures into the improvement of the road conditions seem to be more efficient than road authorities that have used the performance-based contracting. This paper recommends that road authorities use hybrid contracting approaches that include best practices of both traditional and performance-based highway maintenance contracting.

Interdisciplinary Approach to Evacuation Modeling

Evacuations have long been studied within disciplinary boundaries, most frequently in the social sciences and in transportation engineering. Despite the common object of study, previous works integrating these fields’ perspectives are relatively sparse, sometimes leading to evacuation planning models that are divorced from social theory or that observed human behavior. However, a multidisciplinary solution is difficult because many social findings are not directly transferable to optimization formulations or simulation models. Most studies fail to recognize that human behavior and transportation systems are intertwined and that decisions depend not only on the disaster but also on the transportation conditions, options, sociodemographics, experiences, and risk perceptions. This paper reviews these two approaches to evacuation research and proposes a new interdisciplinary approach that merges the strengths of each. The process not only seeks to incorporate empirical and theoretical insights from the social sciences into transportation evacuation modeling but also calls for reexamination of some transportation modeling assumptions in order to improve their mapping in the real world. The result is a new five step modeling process.