Estimation of the entry capacity of roundabouts greatly varies between one method and another in their input requirements, model complexity and estimate accuracy. Several available models for the capacity estimation at approach entries of the roundabouts are tested here and compared for high traffic demand condition. The estimated entry capacities along with the actual entry demand are then com...

Background In the early 1970s, due to concern over asphalt cement supply issues and an anticipated over abundance of elemental sulfur, many organizations Société Nationale des Pétroles d’Aquitaine (SNPA), Gulf Oil of Canada, Sulfur Development Institute of Canada (SUDIC), Texas Chemical Company, U.S. Bureau of Mines, and the Texas Transportation Institute) began to evaluate the potential for su...

The design of a Geosynthetic Reinforced Soil (GRS) wall for internal stability requires computing the reinforcement embedment length against pullout failure. The location of failure plane is important input for this design. The current FHWA design guidelines assume the location of failure plane based on Rankine theory. While this assumption holds true for conventional walls it is unconservative...

This paper presents an integrated neural network-based crack imaging system called " NeuralCrack " to classify crack types of digital pavement images. This system includes three neural networks: 1) Image-based Neural Network, 2) Histogram-based Neural Network, and 3) Proximity-based Neural Network. These three neural networks were developed to classify various crack types based on the sub-image...

Each year, more than 25 percent of highway fatalities in the United States occur at or near horizontal curves, according to the Federal Highway Administration (FHWA). In an attempt to save lives and prevent injuries, some 30 states across the U.S. are applying high friction surfaces (HFS) to improve skid resistance at locations with a high incident of vehicle crashes such as severe horizontal c...

The Federal Highway Administration (FHWA) Office of Highway Planning requires states to furnish vehicle classification data as part of the Highway Performance Monitoring Systems (HPMS). To comply with this requirement, most states use the “F-Scheme” to classify vehicles. This scheme classifies vehicles in 13 classes depending on a number of factors, primarily the number of axles and the axle sp...

Arterials across the United States are experiencing far too many collisions. Agencies tasked with improving these arterials have few available effective solutions. Superstreets, called restricted crossing u-turns by the Federal Highway Administration (FHWA), are part of a menu of unconventional arterial intersection designs that may provide a promising solution. Up to this point, there is littl...

An adaptive neuro-fuzzy inference system (ANFIS) is implemented to evaluate traffic noise under heterogeneous traffic conditions of Nagpur city, India. The major factors which affect the traffic noise are traffic flow, vehicle speed and honking. These factors are considered as input parameters to ANFIS model for traffic noise estimation. The proposed ANFIS model has implemented for traffic nois...

Over the past six years of implementing the Innovative Bridge Research and Construction Program under the Transportation Equity Act, Fiber Reinforced Polymer (FRP) composites technology have successfully demonstrated its potential for structural applications in bridges. The Federal Highway Administration (FHWA) has funded over 120 projects scattered throughout the United States and subject them...

Geosynthetic reinforced soil (GRS) walls and abutments are increasingly used to support transportation infrastructure. A pressing question in their response is the amount of horizontal deflection expected under service loads. This paper presents an evaluation of six methods for predicting the lateral deformation of GRS walls and abutments, namely the FHWA, Geoservice, CTI, Jewell-Milligan, Wu, ...