فهرست مطالب محمد نیری

Development of urban road network is one of the common options to overcome the growth of transportation demand in congested urban networks. The problem of choosing the best combination of projects according to the budget limit is called the Road Network Design Problem (RNDP). In the classical solution of this problem, the travel time index is generally considered as the objective function, while other indices, including topological indices, are also effective in the quality of network service. In this article, the impact of the topological centrality index along with the travel time index on the network design is investigated, and the network design problem is solved by considering the betweenness centrality and closeness centrality indices at different budget levels for the Sioux Falls experimental network. Also, in this article, the betweenness centrality index is evaluated in the conditions of user equilibrium. The results show that minimizing the travel time index does not necessarily improve the centrality index. Therefore, considering the centrality index is effective in answering the problem of network design.

According to forest ecosystem condition in Hyrcanian forests, the fixed numbers can not be useful for determining forest roads width In addifion, these numbers are frequently ignored by the executives and road constructors in order to preserve valuable trees and avoid cutting these trees on sensitive points such as cut slopes and fill slopes. In some cases that roads width is considered based on standard numbers, the vegetative characteristics of edge stands is determined by resl forest roads width. In this study the status of resl width was evaluated based on land slope, earth working limit, vegetative characteristics of edge stands and different slope classes of hillside in shenrood- siyahkal forests. Results showed that the forest roads right-of-way increased with raising hillside gradient (p < 0.05). The mean width of real right-of-way in type A (Fagetoalnetum with 237 stem per hectare and crown cover 68 percent) and B (Fagetocarpinetum with 192 stem per hectare and crown cover 70 percent) were 28.6 and 30.4, respectively. The most overlapped area between real right-of-way and slope of roads was observed in slope classes of 30-40 and 40-50 percent in both types and the lowest overlapped area was seen in slope classes of 50-60 and 60- 70 percent.