Paul E Krugler

Simulation Model to Prioritize Right-of-Way Acquisitions

The costs involved in right-of-way (ROW) acquisition are rapidly increasing, making it more difficult for agencies to complete projects on time and budget. When funds are constrained, the question of what parcels should be purchased first to minimize the overall costs becomes relevant. The answer is related to the timing of the acquisition process and even opens the possibility of early ROW acquisition. Traditionally, early ROW purchases are selected based on expert judgment and on individual analyses, resulting in purchasing too late and having no substantial savings, if any. This paper presents an event-driven simulation model developed by Texas A&M for the Texas Department of Transportation (TxDOT) to estimate costs and predict potential savings under different ROW acquisition scenarios. The Texas A&M Simulation Model (TAMSIM) is used to assist in prioritizing what parcels should be purchased first due to their likelihood of having a substantial cost increase. Four projects (Metro-East, Urban-North, Urban-South, and Rural-West) are used as case studies to demonstrate the applicability of TAMSIM.

A quest for successful pavements in Texas

Building successful pavements requires understanding the factors that contribute to making a pavement succeed. The first question to ask is what a successful pavement is. To answer this question and gather information from successful pavement sections, a two-year project was conducted by the Texas Transportation Institute (TTI) for the Texas Department of Transportation (TxDOT). Information about flexible pavements identified as superior performers has been collected and stored in a database with a user-friendly web-based interface. This database will be used to effectively learn from prior successes. Lessons learned in the past through experience will contribute to better understanding the factors that make a pavement succeed. The aim is to help practitioners improve technical specifications and testing techniques, which will in turn result in more consistent construction of premium pavements. This paper describes the methodology to identify a pavement as successful and briefly describes the Texas Successful Flexible Pavements Web Site. WHAT IS A SUCCESFULL FLEXIBLE PAVEMENT? TxDOT currently uses pavement condition scores, distress scores, and ride scores to characterize performance. Performance levels to qualify as a successful pavement can be expressed through these key parameters. However, pavement success includes consideration of functional performance as well as structural performance. Pavements subjected to different levels of traffic will certainly have different performance and maintenance costs. The performance-maintenance cost relationship varies with the pavement type. Undoubtedly, pavement performance and maintenance costs are key factors to identify a successful pavement.