The following reports from recently completed IDOT-sponsored projects are now available on ICT’s website:
R27-097: Safety Evaluation of Flashing Yellow Arrows (FYAs) for Protected/Permissive (PPLT) Left-Turn Control. This report presents the results of a comprehensive safety evaluation of FYAs for PPLT control, focusing on the left-turn-related crashes—specifically, left-turn opposing-through crashes. Analyses were also performed to assess the effects of the FYA supplemental signs and to evaluate the overall effects of FYAs on two subsets of drivers: older drivers (age 65+) and younger drivers (age 16 to 21 years). The findings of this research, conducted on 164 FYA approaches in the Peoria area, indicate that FYAs for PPLT control improve safety for left-turning vehicles. The results of this research can be used to help make informed decisions about future installations of the FYA countermeasure to improve safety at signalized intersections.
R27-119: Real-Time Information Dissemination Requirements for Illinois per New Federal Rule: Project Extension (Phase II). To satisfy the provisions of the Code of Federal Regulations (23 CFR 511), state departments of transportation and other transportation agencies are required to establish real-time systems management information programs. These programs are responsible for collecting and disseminating travel times, lane closures due to traffic incidents, lane- or road-closing construction activities, and road weather conditions. The objective of this study was to provide the Illinois Department of Transportation (IDOT) with guidance on compliance with 23 CFR 511.
R27-161: Construction and Performance Monitoring of Various Asphalt Mixes in Illinois: 2015 Interim Report. Five experimental projects were constructed to better determine the life-cycle cost and performance of pavement overlays using various types and combinations of reclaimed asphalt pavement, recycled asphalt shingles, and crushed concrete. The asphalt binder replacement varied from 15% to 48% in the experimental sections. The study of these projects prior to construction, during construction, and for a short monitoring period after construction is intended to determine the impact of various pavement conditions, pavement cross-sections, mix designs, and material properties on the ultimate performance of the hot-mix asphalt overlay. This interim report documents the construction and testing to date on two of the five projects in the study.
R27-SP28: Evaluation of the Impacts of Re-Refined Engine Oil Bottoms (ReOB) on Performance Graded Asphalt Binders and Asphalt Mixtures. This report provides findings of a laboratory study that assessed the performance grade (PG) of an asphalt binder modified with various levels of ReOB and the performance of asphalt mixtures using those modified binders. The selected asphalt binder PG for this study was PG 58-28Asphalt binder was blended with two ReOB products at various percentages of ReOB. All asphalt binders (six different blends in addition to the control) were characterized using the SuperPave asphalt binder PG system. Several tests at low, intermediate, and high temperatures were conducted on the studied binders, including rotational viscosity, dynamic shear rheometer, and bending beam rheometer. Tests were conducted at various aging levels. According to the results of the asphalt binder grading tests, even though the binder grade remained the same (i.e., PG 58-28), a reduction in the stiffness of binder at intermediate and low temperatures was observed with increasing ReOB content.