Recently, there has been a significant amount of research related to heavy trucks operating as connected and autonomous vehicles (CAVs). As argued in this paper, understand the potential impact on freeway system CAV technologies, analyses should be conducted using standard US methodological framework. Consequently, paper uses exact Highway Capacity Manual, Sixth Edition (HCM-6) equal capacity p...

In the fall of 1998, the Federal Highway Administration of the U.S. Department of Transportation initiated a series of studies related to the seismic performance of the U.S. national highway system. The research conducted under this study is intended to provide improved tools for evaluating and assessing the social costs and impacts of earthquakes on highway systems and bridges, and to reduce t...

To estimate the capacity of roundabouts more accurately, the priority rank of each stream is determined through the classification technique given in the Highway Capacity Manual 2010 (HCM2010), which is based on macroscopical analysis of the relationship between entry flow and circulating flow. Then a conflict matrix is established using the additive conflict flow method and by considering the ...

R oad user cost is an important consideration in highway economic analyses. The two main components of this cost are (a) motorvehicle running cost and (b) travel time. Highway engineers and economists know that, for road user costs (running costs plus travel time), lower traffic volume usually provides the least unit cost; as volume increases, the cost to the user increases because of congestio...

T his research effort originated during the design of the Central Artery/Tunnel (CA/T) project in Boston. The Commonwealth of Massachusetts, in conjunction with the Federal Highway Administration (FHWA), is undertaking a $5 billion project to widen and depress the existing Central Artery (I-93) through downtown Boston and construct a third harbor tunnel (1-90) below Boston Harbor. During subseq...

There have been several attempts to describe traffic flow behaviour by modelling the relationship between the main variables describing traffic such as speed, flow and density. Some of these models are based on simplistic assumptions and therefore, they are far from being accurate in representing the whole range of traffic conditions (e.g. from free flowing to congested situations). This paper ...

People believe congestion occurs because demand exceeds capacity, so they support initiatives to build additional highway capacity or curtail highway travel demand. Politicians work to bring highway construction projects into their districts; environmentalists support proposals to make transit more attractive or automobile use more costly. This article argues that the facts do not support the b...

In every edition of the Highway Capacity Manual (HCM) until 2016, three levels capacity analysis were defined: operational, project and planning analysis. The level detail each is a function purpose, breadth access available information. Planning determines in earliest stages planning, when small amount data information available. procedure based on AADT forecast macro traffic simulation. Often...