The paper develops a model of traffic flow near an intersection, where drivers seeking to enter a congested road wait in a buffer of limited capacity. Initial data comprise the vehicle density on each road, together with the percentage of drivers approaching the intersection who wish to turn into each of the outgoing roads. If the queue sizes within the buffer are known, then the initial-bounda...

In spite of the strategic importance of the national Portuguese road network, there are no recent studies concerned with either the identification of contributory factors to road collisions or collision prediction models (CPMs) for this type of roadway. This study presents an initial contribution to this problem by focusing on the national roads NR-14, NR-101 and NR-206, which are located in Po...

In this study, we discuss the derivation, applications and the necessity of the traffic dispersion model, which is a nonlinear Poisson equation. Also, the analyses are presented in the content. The model is derived from the interaction among vehicles on a road. Therefore, the traffic pressure can be described by the model and the relation between density and the traffic pressure, which is trans...

Tundra adjacent to the gravel Dalton Highway in northern Alaska was examined for effects of 15 yr of chronic road and road dust disturbance. Road effects at a nonacidic site (soil pH 2 5.0) and an acidic site (soil pH < 5.0) were compared to examine differential susceptibility. Overall, effects on vegetation were more pronounced in acidic tundra. Initial substrate pH appears to control the degr...

The road coloring problem is an interesing problem proposed over 40 years ago by Adler, Goodwyn and Weiss. Hundreds of mathematicians worked on this problem and failed to make the conjecture a theorem. Finally, in 2007, it was proved by a 60-year-old Israeli mathematician, Avraham Trahtman. It turns out the prove was quite simple after Trahtman partitioned the graph into cycles and trees. The d...

In a Vehicular Ad-hoc Network (VANET), the amount of interference from neighboring nodes to a communication link is governed by the vehicle density dynamics in vicinity and transmission probabilities of terminals. It is obvious that vehicles are distributed non-homogeneously along a road segment due to traffic controls and speed limits at different portions of the road. The common assumption of...

1. Studies of large carnivore populations and, particularly, reliable estimates ofpopulation density are necessary for effective conservation management. However, these animals are difficult to study, and direct methods of assessing population size and density are often expensive and time-consuming. 2. Indirect sampling, by counting spoor, could provide repeatable and inexpensive measures of so...

harvesting of timber using ground based machinery is still a common practice around the world. track and road building, and movement of machinery during harvesting operations cause soil disturbance. therefore the aim of this study was to investigate the change in soil properties after logging operation on skid trails (2 years and 7 years after logging) and compare disturbed soil properties with...

With the growth of urban road traffic volume and the increase of road network density, correlation between adjacent road intersections is becoming more and more obvious. An intersection traffic signal adjustment tends to affect the smooth traffic flow of a number of adjacent intersections. Its congestion may gradually spread to a few blocks and regions all around the intersection. Therefore, in...

1.1 Variables The independent variables are x , t : the length along the road and time. The main dependent variables are ρ ,Q : the car density and flux: number of cars per unit length of the road, and number of cars crossing a section per unit time; and U : the mean car velocity. The three dependent variables are related by the identity Q = ρU , (1) which follows from the following considerati...