Yingfeng Li

Mapping Oversized and Overweight Truck Routes with Procedure Based on Geographic Information Systems

Effective and sufficient support for the transportation of oversized and overweight (OS-OW) loads on the nations transportation system is important to a vibrant economy. The availability of advanced tools and technologies based on geographic information systems (GIS) has increased considerably the ability of transportation policy makers to analyze vehicle routing data better. The Texas Department of Transportation recently initiated a research effort to analyze the routes of historically permitted OS-OW loads. The primary objectives of this research included the development of criteria for assigning current and projected OS-OW groups to an improved road network, the identification of strategic infrastructure improvements to accommodate such loads, and the development of optimal and alternative routes for priority load groups between the most common origins and destinations. As part of the project, the research team developed a highly efficient GIS-mapping approach and converted a massive data set of OS-OW permit routes into a GIS format. The mapping approach enabled batch processing and directly queried, retrieved, and stored data from and to an Oracle database. This paper presents part of the findings of this research, with a focus on the GIS mapping process of the historical OS-OW permit routes. The GIS approach will be particularly valuable for those states that are, or will be, automating their process for OS-OW permitting through GIS-based tools. In addition, the research provides valuable lessons for other states that are looking for a workable solution to analyze effectively mass historical OS-OW routing data.

Safety Impact of Pavement Conditions

Pavement condition has been known as a key factor related to ride quality, but it is less clear how pavement condition is related to traffic crashes. The researchers used a geographic information system to link data from the Texas Department of Transportation crash record information system and the pavement management information system. Linking the data provided an opportunity to examine in depth the impact of pavement conditions on traffic crashes. This study analyzed the correlation between four key pavement condition scores and crash rates on a large number of crashes on Texas asphalt nonfreeway roadways between 2008 and 2009. The results overwhelmingly suggest that very good pavement conditions coincide with much lower crash rates compared with very poor conditions. The findings of this study provide insights into how pavement conditions might affect crash rates on different types of roadways. The study also provides critical knowledge that may lead to improvements in safety-oriented pavement design. Because of funding shortages, many state roadways suffer severe pavement deterioration, which may result in increased crash rates, as this study suggests. The findings of this study serve as scientific justification for more adequate maintenance of roadways to avoid further safety deterioration. The researchers recommend that state highway agencies maintain fair or good pavement conditions, at a minimum, on all major state highways. When possible, very good pavement conditions should be maintained to reduce crashes.

Spatial Approach for Assessing Energy-Related Impacts on Transportation Systems

Like many other states around the country, Texas has experienced a boom in energy-related activities in recent years, particularly in the generation of wind power and the extraction of oil and natural gas. Although energy developments contribute to the states energy reliability, they also result in many short- and long-term impacts on the states transportation system. Recently, Texas conducted an evaluation of the effects of energy developments on the state right-of-way, including pavement, roadside, operational and safety, and economic impacts. During the evaluation, the research team developed a spatial approach for the assessment and prediction of energy impacts that used geo-databases of existing energy- and transportation-related data sets. This paper focuses on the development of the geodatabases, their applications in assessing energy-related impacts, and lessons learned during the development and application of the geodatabases. The development of the spatial databases involved significant effort in data collection and processing. The spatial databases that were developed enabled a wide range of queries and reports that helped the research team to understand the distribution and magnitude of energy activities in relation to transportation facilities. In addition to information about data sources and data processing methodologies, the spatial databases provided state transportation officials a useful framework for energy-related transportation planning and assessment of energy impacts and their trends. The valuable lessons and recommended strategies can help other states to fully utilize spatial data sources for understanding energy-related impacts and developing mitigation strategies.