Mitigation Strategies of Reflection Cracking in Pavements

LTRC project Number: 14-4PFReflection cracking is a serious challenge associated with pavement rehabilitation. Practical experience shows that reflection cracking propagates at a rate of 1 in. per year. The primary objective of this synthesis study is to conduct an in-depth literature review of research projects on reflection cracking and a survey of the practices of highway agencies with regard to the types of cracking mitigation strategy used. Based on the results of the literature review and the survey questionnaire, a summarized assessment is presented for each reviewed treatment method. Further, a number of treatment methods were identified for further evaluation. For existing hot mix asphalt (HMA) pavements, crack sealing and overlay, chip seal and open-graded interlayers, full-depth reclamation, and cold-in place recycling are the most promising treatment methods. For existing Portland cement concrete (PCC) pavements, saw and seal, chip seal and open-graded interlayer systems, and rubblization are the most promising treatment methods. Based on the results of this study, the research team recommends that a follow-up study be conducted in order to evaluate the cost-effectiveness of the most promising treatment methods and to develop guidelines for the control of reflection cracking. The developed crack control guidelines will present recommended treatment methods for different classes of rehabilitated pavements in order to achieve adequate control of reflection cracking in a cost effective manner

Minimum Intersection Illumination

20-3SASIO No. DOTLT1000373Numerous prior studies indicated that street lighting improves nighttime traffic safety. However, lighting at unsignalized intersections (e.g., stop-controlled intersections and roundabouts) is not mandatory in some states such as Louisiana. This study aimed to examine whether Louisiana has traffic safety problems due to lack of lighting at its rural and suburban roundabouts and stop-controlled intersections. Underlying this goal, this study set out to (1) record the lessons learned from other states that had implemented partial or full lighting policies or other potentially low-cost countermeasures at their intersections; (2) explore whether the lighting at intersections has a significant impact on the behavior and safety of drivers; and (3) determine the viability of installing lighting at these types of intersections in Louisiana. To achieve these goals, four different approaches were employed: (1) crash data analysis, (2) online national survey among professionals working at the departments of transportation (DOTs) in the US, (3) driving simulator experiment, and (4) cost-benefit analysis

Trends in highway construction costs in Louisiana.

LTRC No. 98-13SSThe objective of this research was to identify and quantify the factors that influence the price of highway construction in Louisiana. The method of investigation involved a literature review and an analysis of construction price records in Louisiana over the last 15 years.The factors that influence construction prices were found to be the inflationary increase in the cost of construction inputs (labor, equipment, and material), characteristics of individual contracts, and the construction environment prevailing at the time of bidding. Contract characteristics found to be significant were contract size, duration, location, and time during the fiscal year in which the contract was let. Contract conditions found to influence contract prices were the total volume of contracts bid, variation in the bid volume, number of plan changes, and introduction of changed contract specifications, standards or practice.The most influential factors in determining the cost of construction are the price of labor, equipment, and material. However, changes in contract characteristics and the contract environment also have an impact, causing fluctuations or incremental changes to the price of construction. The most important of these are contract size, duration, and location among the characteristics of individual contracts. Among contract conditions, number of plan changes, and changes to contract specifications, standards, or practice, are the most influential.The impact of the factors on the cost of construction has been captured in a model which presents construction costs in terms of a construction price index similar to the Federal Highway Administration\u2019s Federal-Aid Highway Construction Composite Bid Price Index. The model closely reproduces past construction cost records when supplied with either disaggregate (i.e. contract level) or aggregate data. The model was used to predict future construction costs. Forecasts of labor, material and construction equipment costs were used together with the assumption that current contract characteristics and conditions will be maintained in the future. Under these assumptions, the model estimated that construction costs will double between 1998 and 2015 as measured in current dollars

Mitigation Strategies of Reflection Cracking of Pavement [Tech Summary]

LTRC Project No. 14-4PF, SPR: TT-Fed/TT-RegThe RAC Region II has initiated a collaborative research program consortium through the Transportation Pooled Fund (TPF) Program. The research program is called the Southeast Transportation Consortium (STC) and is intended to encourage coordination among member states, as well as provide resources and management of collaborative studies. The Consortium intends to address high priority transportation research topics of common interest to the southeastern and adjoining states. Louisiana serves as the lead agency in the STC

Effect of Fillers on the Moisture Resistance and Performance of HMA: Research Project Capsule [23\u20131B]

TT-Fed/TT-Reg-6The main objectives of the proposed study are two-fold: 1. To evaluate the effects of various types of inert and active fillers on the moisture resistance and laboratory performance of asphalt mixtures. 2. To propose change to the specifications to optimize the use of mineral fillers in hot-mix asphalt (HMA)