and follow-up headway values based on a comprehensive evaluation of roundabouts throughout the United States. The recommended operational models by NCHRP 3-65 will be incorporated into the next update of the Highway Capacity Manual (HCM). Although this NCHRP study contains a significant amount of data (including more than 500 h of video at various roundabout locations), the data do not include ...

The Long Term Pavement Performance (LTPP) program is a 20-year study of inservice pavements across North America. Its goal is to extend the life of highway pavements through various designs of new and rehabilitated pavement structures, using different materials and under different loads, environments, subgrade soil, and maintenance practices. LTPP was established under the Strategic Highway Res...

Highway automation has recently enjoyed renewed research interest as a method for solving highway congestion problems. To determine the feasibility of automated highways, it will be essential to estimate the automated highway benefits. A critical task in the analysis of automated highway benefits is to estimate the potential increase in highway capacity. This paper uses deterministic approximat...

The idea of vehicle-highway communications sufficient to assume driving functions for the driver is not new. Researchers have articulated both its value and feasibility for several decades; and military and vehicle manufacturer test facility developments have proven the concept’s viability. As mounting congestion conflicts with environmental constraints, the Automated Highway System (AHS) promi...

Manual surveying methods have long been used in the field of highway engineering to determine the cross-slope, and longitudinal grade of an existing roadway. However, these methods are slow, tedious and labor intensive. Moreover, manual survey methods almost always require partial or full lane closure resulting in traffic delays, increase in costs, and inconvenience to the travelling public. In...