جستجوی مقالات مرتبط با کلیدواژه "مدیریت تقاضا" در نشریات گروه "عمران"

Nowadays, traffic congestion is a major problem in metropolises that affect daily life. Imbalance between supply and demand causes conjestion. Demand management is used to balance demand and supply, since has more reasonable cost and less restrictions in comparison with increasing transportation supply. One policy in order to manage the demand and reduce Tehran traffic conjestion is to implement flexible working hours since Mehr 1401. In this study, the effect of flexible working hours on traffic congestion has been investigated by using length of Tehran congested roads. The linear regression has been modeled based on the length of traffic congestion of the third week of Mehr 1398 before the Covid-19 epidemic in comparison with the third week of Mehr 1401. It was expected to face more road congestion due to the traditional education after the virtual education during Covid19 epidemic, user behavior changes, increase in usage of private cars. Nevertheless by implementing flexible working hours, Tehran traffic congestion has been far more suitable except the Limited traffic zone than the urban management's prediction.

Due to the problems caused by personal car use, demand management policies have been developed, which result in reduced use of personal vehicles. It is generally accepted that demand management policies are classified into two types: hard or soft. In the case of soft politics, people tend to be receptive, while being combative to hard policies. In the case of Tehran's odd or even zone, the purpose of the paper is to examine the role of latent components in the acceptance of demand management policies. To address the issue and measure the resistance of individuals to accept the car reduction policy, we designed a stated preference questionnaire and measured the acceptance rate in terms of behavior change. Changes in behavior patterns and the choice of private car mode are methods used to determine acceptance rates. The acceptance of policies can be assessed by identifying their hidden nature via the value-belief-norm theory. In this theory, value influences the norm through belief. So, people who know that they should cut down on the use of the private car are more inclined to accept the use of private cars. Examination of the adoption of private car prohibiting policies under changing behavior in different periods of implementation of a private car is debatable. In this study, more than 500 questionnaires were distributed randomly among Tehran citizens including couples or single individuals considering the scope of the traffic plan traveled by transit vehicles. Using the multiple logit model, this study investigates the changes in people's behavior toward accepting the policies of reducing the use of private cars in two short-term and long-term periods. Results show that individual values and norms are effective factors in changing users' behavior over short- and long-term periods.

The increasing demand for private cars and the unbalanced and dense growth of land-uses in the north of Tehran metropolis have caused fuel supply stations (gas stations) to always face the demand queue. On the other hand, the exorbitant price of land in these areas does not make the construction of a new location cost-effective. Demand management policies such as increasing the cost of using the facility are the possible solution to solve such problems. In this paper, the gas station users' data in the north of Tehran were collected using the stated preference method and analyzed using SPSS statistical analysis software to define the agent features and build agent-based modeling. The survey results were used to define the characteristics of factors and interactive rules in NetLogo simulation software. Then, the existence of a fast-passing line (with five different pricing scenarios) was simulated compared to the normal condition. The results showed that although the price increase scenarios (scenarios 4 and 5) are more welcome by relying on the statistically-based stated preference method, the agent-based simulation shows the popularity of cheap scenarios (scenarios 1 and 2) based on the interactive behavior of people are more valid. This indicates that the stated preference method's responses cannot be reassured in cases where interactive behaviors exist. Also, due to the imbalance of supply and demand due to the region's context, creating a tolled high-speed passing line is an effective solution to adjust the queue length and reduce waiting time.

Nowadays considering to a scarcity of water resources and increasing growth of population and water demand, Water resource management be deemed to be essential. One way of managerial to deal with the crisis of water scarcity and protect existing water resources, is management of the Demand and water use in the urban sector. Iran, with an average annual rainfall of 250 mm, is one of the dry countries in the world. The rapid growth of the population over the past few decades and the lack of attention to its control over the country's planning priorities and the inappropriate pattern of energy and water consumption have faced Iran with serious challenges in this regard. Considering the significant reduction in water resources available on a global scale and the importance of achieving sustainable development goals, the study of factors affecting water resource management has been considered more than ever. In order to compare the country's situation in the region, comprehensive information is needed on the amount of per capita consumption and the minimum amount of water needed to achieve a human development pattern.So far in Iran, a study has not been conducted to establish a systemic relationship between the parameters affecting the consumption pattern in the urban sector and modeling the interaction between the pattern of consumption and per capita water as well as the sources of urban water supply using a dynamic system approach.

Water demand management policies (WDMPs) are being proposed as a solution to water scarcity. Applying any of WDMPs can have far-reaching consequences even on the urban infrastructures like wastewater systems. However, studies on the effects of WDMPs often focused on the water sector, and there is a research gap in the wastewater section. Therefore, in this study, the impact of the application of WDMPs on sewage systems from a social point of view has been evaluated during different scenarios of demand reduction. For this purpose, the Social Life Cycle Assessment (SLCA) method, which is a subset of life cycle thinking, has been used. In this regard, Baharestan city (located in Isfahan province) is selected. The groups (stakeholders) affected by the social effects of WDMPs on wastewater systems have been identified and their characteristics have been determined. Stakeholders are social and local community, workers and consumers. Then, by compiling a questionnaire and using the opinion of experts in this field, the Analytic Hierarchy Process (AHP) method has been used for scoring. Then, taking into account the intensity of the effects of each indicator in each scenario, the social score of all scenarios is obtained. The results show that social and local community has the biggest weight than other stakeholders (wight of 0.45), and safe and healthy living condition is the most important indicator of it. Also, the scenario that has the least decline in water consumption and sewage production is socially better than others.

Traffic management in cities necessitates the implementation of comprehensive strategies and correct scheduling of demand management in order to reach sustainable development goals. Transportation is the main contributor to urban air pollution imposing high cost to communities. Emission from mobile sources in Tehran is responsible for 85 percent of the total air pollutant emissions. Therefore, assessment of emission rates in different districts may be used as the base for air quality management decisions. Due to the complexity of effective policies that lead to environmental sustainability for reducing the emissions of air pollutants caused by transportation using Multi Criteria Decision Making (MCDM) approaches could be an effective and the most appropriate approach.
 Sadr overpass is one of the east to west main corridors in Greater Tehran Area and embeds a large amount of traffic volume. Therefore, assessing different and alternative traffic scenarios and its modeling incorporating air pollution concerns, promotes imposition of the most environmentally preferred traffic demand management policies. This study aims to investigate different alternatives to access Sadr Overpass of Tehran using different ramps and estimating the air pollution caused by the traffic volumes in each access mode. These scenario alternatives have been evaluated using MCDM. Therefore, the different access routes via ramps of Sadr Overpass to its main lanes are considered in terms of the two formerly implemented scenarios. The first implemented scenario is defined as the air pollution caused by the traffic volume due to limitation of access that was implemented before 21 June of 2017. In this period of time, in the east to west direction, the limitation of access to Sadr Overpass was imposed via lower level Sadr ramp in between 7 to 10 AM and during the closure of this ramp, vehicles could access the overpass and Niayesh Tunnel via Qeytarieh and Kaveh ramps. In other side of the overpass, the first ramp leading the lower level is closed at 15 to 21 and vehicles could not access Sadr Expressway via this ramp. The second scenario is defined at the period of time that the limitation of access in both directions, was imposed all over during the day time permanently that is from 21 June 2017 till now.  Air pollution caused by each mode of transportation is modeled using IVE that is an International Vehicle Emission Model to simulated emissions from motor vehicles. The IVE model uses local vehicle technology levels and its distribution and includes emission factors for estimating the air pollutants. Furthermore, these scenarios have been compared using Multiple-Criteria Decision Making approach and the evaluated criteria are the emission rates of motor vehicles, velocity and level of service (LOS) of the expressway. The results show that the evaluated scenarios are ranked as per their level of priority as the first and the second implemented scenarios, respectively. Also, it is shown that in the east to west direction, closure of lower level Sadr ramp in the morning peak time of traffic volume reduces the emission rates of CO pollutants by 10 percent  in that time. Similarly, in the west to east direction, limiting the access to the lower level Sadr ramp during 16-17 hours reduces the CO emissions by 3.5 percent.

Among the major components of an airport access are probably not attract much attention at first sight, However, equitable access to attract passengers (especially domestic) is effective. As there is no proper access create repulsion and reduce the utility of the airport, It can be stated that the airport can be an important factor in the success of the quality and quantity of access to be. International Airport Imam Khomeini is the exception to the rule. In this regard, the existing access and hit the airport has been examined in previous studies While recognizing the current situation in this field to provide a tool for future decisions. In addition, the solution integrates with existing travel demand and supply supply supply needed to meet demand, Demand management can be used as a means to optimize supply and develop costly network of passages noted. Accordingly, in the present study demand management scenarios aiming at reducing the peak demand hours of Tehran and transfer it to other population centers are defined. Including the policy that live scenario can be employed in a new city airport in birds, Change in working hours from 2 hours to 3 hours, and strengthening the role of public transportation in Imam Khomeini International Airport (RA) named. Simultaneous realization of state policy in demand management, And acceptance through 2000 equivalent passenger volume of each band, By creating two bands crossing the highway in each direction for Tehran – Qom, One band crossing the highway Tehran - Saveh and one band crossing the south of Spain, Spain northern and Parand available Be responsive to vehicle traffic volumes resulting from land uses in airport, The design was based on a time horizon of peak.

Nowadays, with the increasing growth of vehicles and increasing of trips and also financial constraints and roads development, transportation network managers eager to follow transportation demand management. Application of traffic restraint is one of the methods that reduce the supply and demand transportation. In this paper, to investigate the effects of trip restrictions for heavy vehicle, driven old road Qom - Tehran and its alternative paths during the traffic restraint for heavy vehicles, there have been studied. Traffic information in three different periods of time including restriction time, the same period in the weeks before and after the restriction of detectors mounted on each road were obtained. Based on the results observed during the restriction period in addition to reducing the number of heavy vehicles, passenger cars are too low. Also, Assumption was that the goal of banning heavy vehicles traffic on the old road and transfer to Tehran-Qom freeway has not been met. Based on the data recorded in road alternatives, it cannot be observed a significant change in traffic volume of heavy vehicles over the period of time.

Restricting passenger cars in congested urban areas is one of the conventional methods for pollution reduction and demand management. Although enforcement of plate number rationing scheme in Tehran (Even- Odd Zone) was in order to manage the traffic demand، this scheme is currently inappropriately controlled manually by police visual surveillance at the entrances. In this way، some problems such as low flexibility of policemen and a significant number of violations due to human error stress the necessity of using mechanized control for enforcement of plate number rationing zone. In this research، the authors have attempted to maximize violation detection by locating cameras at the entrances. The suggested model in this research is a binary model and covers various constraints such as budget constraints، staffing and minimal number of roads in a different road hierarchy. Because the number of streets that should be controlled by cameras is related to allocated budget، the sensitivity analysis of this budget is done and violation detection is presented. The results of sensitivity analysis indicate that violation detection would be increased significantly up to the approximate cost of 6. 55 trillion Rials. The results of this research and violation detection per different allocated cost would be an effective tool for authorities to allocate funds for this project.

Limited capacity of transportation infrastructures for development of new facilities and expansion of the capacity of the current facilities, in addition to the high cost of so many supply management policies, whether in the supplier’s or the transportation services user’s view, suggest to the transportation planners the fundamental necessity of referring to demand management policies. The growing rate of implementing travel time information systems, in order to enhance the performance and level of service within transportation networks, has stimulated planners to generate more sensitive models with capability of quantitatively assessing the benefits of introducing traveler information systems. A superiority of stochastic approach of traffic assignment is its higher flexibility in modeling commute behaviors than a deterministic model provides. In order to demonstrate this potential flexibility, we have suggested a multi-class version of stochastic traffic assignment with paired combinatorial logit route choice kernel—one of the most advanced discrete choice models applied in network analysis—being able to evaluate benefits of serving transportation networks by traveler information systems.