Browsing by Subject "Federal Highway Administration"
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Item Evaluation of freeway work zone merge concepts(2013-12) Kurker, Michael Gerald; Machemehl, Randy B.Using microsimulation software, with a focus on VISSIM, the analysis of different applications of merge concepts through delay and safety is presented in this thesis. In order to appropriately draw conclusions and usage trends of different merge concepts from the microsimulation software, early merge, late merge, and signal merge were first explored in a thorough literature review. While focusing primarily on delay, queues, and safety, this thesis essentially provides an introduction to determining the ideal merge concept on freeway work zones for varying roadway configurations, roadway conditions, and user demands, among other factors. In addition to delay and queuing analysis completed using VISSIM, the Federal Highway Administration’s Surrogate Safety Assessment Model (SSAM) was used to address the effects of implementing signal merge on rear-end and lane-change conflicts. Compiling the VISSIM microsimulation outputs and SSAM signal merge safety outputs, general conclusions and decisions were provided. While this thesis provides determinations of ideal merge concepts for a variety of cases, it is important for the next researcher to assess some of the assumptions that were made, to ensure that they would not significantly affect the results and analysis.Item Improving transportation project delivery with NEPA assignment : lessons learned from California and Texas(2016-05) Miller, Brian Joseph; Zhang, Ming, 1963 April 22-; Loftus-Otway, LisaThe Surface Transportation Project Delivery Program, or NEPA Assignment, authorizes the delegation of federal powers under the National Environmental Policy Act (NEPA) to State Departments of Transportation (DOTs) for project reviews, permitting, and approvals. This program builds on past legislative efforts to streamline environmental reviews and documentation for the purposes of expediting federally funded highway projects by state DOTs. This research provides an interpretation of key roles, responsibilities, and requirements following the state’s assumption of the Federal Highway Administration’s (FHWA) responsibilities for NEPA reviews, decision-making, and formal consultation with resource agencies. The report draws exclusively from the California and Texas’ NEPA Assignment programs and progress made to date. In doing so, the report highlights the checks and balances of the NEPA Assignment program through monitoring performance management by both the DOTs and the FHWA, and addresses key administrative challenges during implementation from the state’s perspective. The report concludes with recommendations and lessons learned from the both states.