As the asphalt pavement industry advances toward the use of higher reclaimed asphalt pavement (RAP) contents in asphalt mixtures, it becomes increasingly important to accurately assess the quality and variability of RAP to ensure consistent pavement performance. Final Report for NCHRP IDEA Project 245: Simple and Rapid Tests for Assessing Quality and Consistency of Reclaimed Asphalt Pavement (RAP) for Recycled Asphalt Mixture Applications documents a project that investigated innovative methods for dete...

Cantilevered traffic signal structures are critical components of urban infrastructure. However, their slender, cantilevered design makes them particularly vulnerable to wind-induced vibrations, which can lead to fatigue failures at the pole-to-mast arm connections—locations where stress concentrations are highest. Despite ongoing research into fatigue-rated joints and passive damping devices, limited attention has been given to the real-world aerodynamic behavior of these structures under natural wind ...

Highway construction workers are regularly exposed to loud and complex noise environments from equipment, tools, and nearby traffic. While hearing protection equipment (HPE) is essential for preventing hearing loss, it often blocks important warning sounds—such as backup alarms or vehicle intrusion alerts—that are vital for worker safety. T The TRB IDEA (Innovations Deserving Exploratory Analysis) Program's NCHRP IDEA Final Report for Project 247:  Augmenting the Hearing of Safety-Critical Sounds fo...

Horizontal curves, comprising only about five percent of highway miles, account for a disproportionately high number of fatal crashes, nearly 25 percent. Excessive driving speed on curves is the leading cause of these run-off-road crashes, due to vehicles exceeding the amount of friction available. Understanding existing curve safety conditions, such as advisory speeds, is crucial for planning and designing safety countermeasures. The TRB IDEA (Innovations Deserving Exploratory Analysis) Program's NCHRP ...

Dynamic modulus (E*) values significantly influence the estimates of pavement performance and life, and they are a key input for pavement design programs. Therefore, quick and accurate determination of E* values of asphalt mixtures is crucial for designing long-lasting pavements, saving taxpayers money, reducing emissions, and reducing traffic delays. The TRB IDEA (Innovations Deserving Exploratory Analysis) Program's NCHRP IDEA Final Report for Project 242: Development of an AI-Powered Dynamic Modulus T...

Current state of practice methods to determine mixing and compaction temperatures for asphalt mixtures fail to reasonably explain the mixture workability mechanism and do not consider other important properties of asphalt mix such as aggregate properties and mix gradation. The TRB IDEA (Innovations Deserving Exploratory Analysis) Program's NCHRP IDEA Final Report for Project 246: Develop a Method for Selecting Low-Energy Mixing and Compaction Temperatures for Asphalt Mixtures Considering Asphalt Lubricat...

Retroreflectivity plays a crucial role in pavement markings as it enhances nighttime visibility for drivers. Yet, due to budget constraints, many state U.S agencies rarely monitor the retroreflectivity of their markings, and instead, restripe their markings based on visual inspection or fixed schedule. The TRB IDEA (Innovations Deserving Exploratory Analysis) Program's NCHRP IDEA Final Report for Project 237: New Tool for Predicting the Retroreflectivity (RL) of Pavement Markings details the development ...

More than 70 percent of the roadways in the United States are in areas affected by winter weather. Accidents on the roads because of winter weather account for over 7,000 fatalities and over 1 million accidents annually in the U.S. alone. Studies show that there is a significant increase in accidents due to icy road conditions. The TRB IDEA (Innovations Deserving Exploratory Analysis) Program's NCHRP IDEA Final Report for Project 239: A Real-time Warning System Empowered by Dielectric Ice Sensors for Bri...

The design, fabrication, and installation of cross-frames for curved and highly skewed steel girder bridges can be difficult and time-consuming. In these bridges, the girders twist and deflect, creating differential vertical displacements and rotations such that cross-frame fit can result in multiple challenges. The TRB IDEA (Innovations Deserving Exploratory Analysis) Program's NCHRP IDEA Final Report for Project 227: Adjustable Cross-frames for the Erection of Steel Girder Bridges develops, numerically...

A sensor system embedded in ethylene propylene diene monomer (EPDM) rubber strips, utilizing force transducer technology to detect tire widths, vehicle classifications, and wheel wander at highway speeds can be deployed in high-traffic corridors to monitor wide-base tires and their impacts on pavement performance. The TRB IDEA (Innovations Deserving Exploratory Analysis) Program's NCHRP IDEA Final Report for Project 238: Low-Cost Sensing System for the Detection and Classification of Wide Base Tire Types...