the supporting posts and soil. Impacts with a higher speed but shallower angle can also cause more distributed rail-and-post deflection. The amount of deflection that can be sustained by guardrail before its safety is compromised is a major concern. Maintenance crews and highway agencies are often forced to balance the expense of continual repairs against the potential liability if the damaged ...

PURPOSE The Federal Highway Administration (FHWA) proposed guidelines for highway design to increase the safe driving ability of older drivers; however, little empirical evidence exists to support the effectiveness of these guidelines. The purpose of this study was to investigate the effects of implementing these guidelines (in 4 pairs of intersections) on safe driving performance of older and ...

One of the goals that the Innovative Bridge Research and Construction (IRBC) program, sponsored by the Federal Highway Administration (FHWA), wishes to achieve through sponsored research projects is the concept of an economical, durable, short-span bridge that reduces construction time. Delaware County, Iowa took a step in that direction through the construction of a 64 ft. long bridge comprise...

FOREWORD This research project was performed to investigate the possibility that, by measuring the dynamic response characteristics of a bridge substructure, it might be possible to determine the condition and safety of the substructure and identify its foundation type (shallow or deep). Determining bridge foundation conditions with this approach may be applied to quantify losses in foundation ...

This study aims to assess the Travel Time Reliability (TTR) in urban areas Irbid city, Jordan, using a mobile application (Ultra GPS Logger), which retains current location, speed, and time every three seconds. The evaluated TTR at Origin-Destination (OD) level segment level. Each OD was divided into several segments with different interruption types determine have lowest reliability most exten...

Interpretation of IE data have been carried out by analyzing signals in frequency domain to determine the maximum frequency. However, current peak method can be inaccurate. The purpose this research is introduce features that used for effective classification and interpretation bridge deck evaluation through statistical analysis Naive Bayes classifiers. dataset contained collected from eight sl...

Adaptive traffic signals have had a checkered history in the U.S.A., and many professionals are unsure about whether the benefits justify the costs. The FHWA sponsored research into adaptive signals and several systems have now been developed to the stage where demonstration projects are underway (e.g., RHODES and OPAC). At the same time several adaptive systems (e.g., SCATS and SCOOT) have bee...

This paper examined the day-to-day variability of the journey-to-work trips, including the departure time, route choice, and trip chaining behavior, using GPS-based disaggregate morning commute data of 56 drivers during a one-week period. Data were collected from the ongoing instrumented vehicle projects in Atlanta sponsored by NHTSA and FHWA. The paper examines alternate measurements of the da...