The researchers found that the main challenges leading to project inconsistencies are insufficient communication over the changes to projects design concept and scope, cost, and estimated letting date. The research team developed a Project Consistency Guidebook (PCG), a Supplementary Information Document (SID), and a project consistency checklist. The guidebook explains how project planning and development interact with the regional and project level air quality conformity process, and details procedures and tools that TxDOT and Texas Metropolitan Planning Organizations can use to understand and maintain project-level conformity and project consistency with applicable transportation plans and programs. The SID provides an overview of the subjects relevant to project consistency. The project consistency checklist serves as a guide to keep track of the changes to a project.

Publication date: 2016-10-30

Maintaining Project Consistency and Conformity PDF

This memorandum summarizes work performed by Texas A&M Transportation Institute (TTI) staff in Fiscal Year (FY) 2015 on investigating the use of Texas Department of Transportation’s (TxDOT) Statewide Traffic Analysis and Reporting System II (STARS II) for mobile source air quality modeling and related uses. STARS II comprises a database of traffic activity and a web-based geographic information system (GIS) that can be used to search for and download traffic count data. This report provides a brief overview of the STARS II system, and discusses the importance of traffic data for air quality research. Our study methodology involved a structured brainstorm session among Air Quality and Transportation Engineering professionals to generate an expansive list of ideas for how STARS II data could be used in Air Quality studies. The study team then selected one of these ideas to perform a case-study. The case-study involved Truck traffic on the I-35 corridor between Laredo, TX and San Antonio, TX, and tested the ability of STARS II to provide data suitable for addressing a “real world” air quality problem. The conclusions from the study are that STARS II offers an important and currently underused data resource for air quality studies.

Air Quality Performance Measures PDF

This technical report discusses the development and study of emission characteristics from a variety of HDDVs in the HGB area. The project focused on understanding and characterizing the HDDV emissions for representative fleets in the HGB area. The research team explored a variety of vehicle fleets and identified the city of Houston (COH) fleet for use in the study. Thirty HDDVs were selected from the COH fleet to represent both high emitter (HE) and non-HE vehicles. A set of 12 HEs identified based on opacity testing, and a randomselection was used for the non-HEs. The research team performed a driving test measuring various parameters such as speed, acceleration, engine load, and in-use emissions. Additionally, they performed an idling emissions test under controlled conditions in an environmental test chamber. The measured emissions were also compared to estimates obtained using the Motor Vehicle Emission Simulator (MOVES). This testing allowed the research team to learn the characteristics of HE emissions and compare them to emissions for the general fleet (non-HEs).   

Characterization of Exhaust Emissions PDF