Innovative Intersection Traffic Modeling: Tips, Tricks, and Things Often Overlooked

INDOT is actively pursuing innovative intersection treatments across the state to improve safety and mobility. Traffic analysis of these intersections is critical to ensure they will perform as intended, but can often be complex. This session will explore several best practices for modeling innovative intersections and will highlight commonly overlooked elements that are key to proper traffic analysis

Innovative Intersection Public Involvement: Strategies That Work

This presentation will share best practices for effectively engaging the public and local stakeholders during the development of innovative treatments. We will cover why innovative treatments work; their selection process; case studies from finished projects; and tips and tricks for effective, positive engagement and collaboration. This presentation will benefit project managers, public involvement professionals, and engineers involved in developing innovative treatments

Cost-Effectiveness of Converting Signalized Arterials to Free-Flow Facilities

Traffic signals on four-lane divided signalized arterials impair mobility and exacerbate traffic congestion, driver frustration, crash risk, and overall user and community costs. This study examined the economic feasibility of converting this roadway type to freeflow corridors. A free-flowing facility does not refer to a freeway, but rather, a facility that is free of traffic control devices (such as traffic signals and stop signs) on the mainline. At the intersection level, four intersection alternatives were considered: signalized intersection (do nothing), two-way stop-controlled (TWSC) intersection, J-turn and interchange. The study developed a decision framework that evaluates the overall performance of upgrade alternatives at the intersection and corridor levels in terms of the total life-cycle agency and user cost associated with mobility and safety. It was found that when traffic volumes are low, the TWSC intersection has superior mobility performance over J-turn and signalized intersection. Interchange and J-turn exhibited superior safety performance compared to TWSC and signalized intersections. Interchange always has the highest mobility performance particularly where the major and minor road traffic volumes are high. The study also developed nomographs to present rankings of the alternatives and established decision boundaries based on major and minor road traffic volumes. The nomographs can help INDOT identify the appropriate intersection type based mainly on the major and minor road traffic volumes. At the corridor level, the two conversion alternatives are free-flow corridor (with a mix of TWSC, J-turn and interchanges) and freeway corridor (interchanges only). Overall, the evaluation results were found to be sensitive to traffic volumes and weight ratio of the agency cost to user cost dollar. The study also developed a spreadsheet program to facilitate implementation of the decision support framework

Statewide Screening of Signalized Intersections for Capacity Improvements

Identification of congested traffic signals that require capital investment to increase capacity has historically been a time-consuming process. Signalized intersections with congestion were analyzed to see if they could be improved through retiming, and capital investment was only considered if retiming is deemed infeasible. Automated Traffic Signal Performance Measures (ATSPMs), and more recently, signal performance measures (SPMs) derived from connected vehicle (CV) trajectory data, have already been used to streamline the process of identifying signalized intersections that can be improved through retiming. However, to date, similar efforts have not been used to identify intersections that may benefit from capital investment. This study developed a CV-based methodology to assess whether signal retiming could potentially be feasible for a given signalized intersection using the split failure percentage (SF) SPM. For intersections where retiming is not feasible, a ranking metric of critical path split failing trajectory counts (SfnCP) was developed for prioritization by capacity improvement necessity. This metric was implemented statewide to over 2,300 INDOT-managed signalized intersections over a 17-month timespan to demonstrate the effectiveness, efficiency, and scalability of the proposed approach. Additionally, the utility of CV data for similar ranking of unsignalized intersections and road segments was also discussed. To aid INDOT engineers with rapid identification and prioritization of intersections that can be considered for capital investments, performance reports containing various attributes were proposed and generated

Effects of Duty Schedule Variance and Overtime on the Job Satisfaction and Turnover Intentions of USAF F-16 Crew Chiefs

This thesis empirically assessed how duty schedule variance and overtime affect the job satisfaction and turnover intentions of USAF F-16 crew chiefs. A survey was completed by 346 active duty USAF F-16 crew chiefs regarding their perceptions of duty schedule variance, overtime, job satisfaction and intent to leave the Air Force. Theory suggests that turnover behavior is a multistage process that involves organizational, individual, and attitudinal components. Using multivariate correlation and regression analyses, plausible evidence was found to support the idea that duty schedule variance and overtime plays a role in USAF F-16 crew chief turnover intentions via job satisfaction. Additional evidence supported the theory that these path relationships changed in strength for demographic sub-categories based on age, but not for education, length of service, marital status or number of dependent