نشریه فناوری حمل و نقل
پیاپی 23 (پاییز و زمستان 1393)

This paper aims to assess the condition of empowering at Tehran urban and suburban metro operation co. and its relation with Quality of Work Life (QWL). For QWL، Walton model with factors of growth opportunities and continuous safety، lawfulness in the work، the total life space، social integration، and development of human capabilities are selected. For empowering، six factors are selected، knowledge and skill base، communicational، cultural and motivational، structural، managerial and strategic. These relations investigated by questionnaire. Survey was conducted among managers and professionals of the aforesaid organization. The results show that there are 30 correlations and 6 discontinuities. The structural، knowledge and skill base، communicational، cultural and motivational، strategic، and managerial factors have the greatest impact on QWL respectively. Empowering factors except communicational have a mean lower than average and communicational، cultural and motivational، strategic، knowledge and skill base، structural and managerial factors have the highest mean respectively. The priority of this organization must be focus on the structural and knowledge and skill base empowering which have low mean and high importance.

Since road accident is one of the most important factors in fatality، and cause financial and physical damage. Therefore، safety stability is one of the fundamental aims of transportation in different countries. Allocation of annual budget for increasing safety level is one of the government activities for reducing traffic crash. Since the budget always is not enough، equilibrium between existing budget and problem is necessary. The most effective allocation should be implemented. Since traffic tool is one of the most important factors in reducing traffic crash، this research provides a model for choosing the best safety traffic tools by considering existing budget and number of accidents. One of the specifications of this model is consideration of more than one safety action، simultaneously. Finally، as a case study and for the sake of research validation، 91km of Urmia-Salmas road، in west Azerbaijan province، was modeled. The outcome of this case study was proved to be satisfactory in terms of a set of best safety tools measures.

Roads have different roles in the economy of cities. Roads can influence on direction of development of the city and therefore increase the cost of land and wealth distribution. In this study، it is tried to have a more clear understanding about costs and benefits of these kinds of roads، with descriptive- analytic method to find out the effects of ring roads on the economy of cities as after construction، it does not harm the economy of the city and there will be improvement on it. The importance of this research appears especially where the cities are located between the roads with service roles. In this research، the north ring road of Damghan was chosen as a sample. Data for this research was obtained through field method by gathering traffic volume counts، photographs and interviews with city managers، traffic Police and owners of service centers and also by documents. The results indicate that the best solution in current situation is organizing all of these three roads through the passengers’ goals، investments، increase in revenues of service jobs and the city and economy improvement.

There is a need among railway track maintenance and management for a better understanding of the railway track systems and for improved predictive techniques. Railway maintenance procedures form an integer part of expenditures in railway industries. The aim of this research is development of an appropriate system for maintenance of Iranian railway track in a management system frame work. In this context، current maintenance management systems in the USA، Europe and Asia were reviewed and 5 systems were identified (RAILER، ECOTRACK، TRACKS، RAMSYS and DTM). The research indicated that to characterize the railway and maintenance approaches in Iran، a new strategy was made in order to improve maintenance and management decision system in Iranian railway. This research identifies and classifies the best system for every characteristics such as failures، traffic and facilities، and also provides a system lines on the basis of the quality and analysis track information.

Some of today’s most vexing problems، including congestion in streets، climate change، and air pollution result from excessive dependence on automobiles. Following this challenges، planners and urban authorities have been promoting policies which improve the quality of the built environment for pedestrians and rein in automobile use. In this regard، this research which is a correlation study aims to investigate the relationship of socio-economic and the objective variables of urban form with two variables including frequencies of auto trip and frequencies of walking trip. The variables have been captured using a self-administrated questionnaire and the analysis of GIS databases. The ANOVA tests demonstrate that there are statistically significant differences in mean both auto and walking trips in different neighborhoods. Moreover، the results of correlation analysis indicate that frequencies of auto trip have more statistically significant relationship with socio-economic variables. Accounting for socio-economic variables، many objective variables of urban form including residential density، parcel density، intersection density، vertical mixture، and so on are associated with auto and walking trips.

The pavement management system (PMS) is a synchronous and regular procedure to conduct all of the works related to the pavement maintenance and repair. Through a proper PMS، sustainable and correct decisions in maintenance، repair and rehabilitation of pavements are possible. Pavement management is proceeded at two levels: Project level and Network level. Pavement management at project level copes with detailed design decisions for each project separately and at network level it copes with building a priority and schedule program for construction، maintenance and rehabilitation of a new pavement along with budget limitations. PMS software input includes 3 types of data: road inventory، pavement situation and maintenance and repair strategies and their costs. The aim of gathering pavement deterioration data and their reasons is identification of the situation for each road section based on the scale of pavement deterioration. The next step is classification of pavements based on the scale of pavement deterioration. The PMS software identifies the potential repair options for each section and estimates the repair costs and then prioritizes and determines the most economic methods of maintenance and repair. Finally، it represents the result of data analysis as a detailed report including prioritized maintenance options for each section along with their costs.

Porous asphalt is a gap graded mixture. It has many advantages including the friction improvement، noise reduction of passing vehicles on the pavement surface، elimination of hydroplaning phenomenon and light reflectivity and permeability increase. It ultimately increases the safety and reduces accidents. In the initial period operation of the porous asphalt due to the surface coating of aggregate with bitumen، the skid resistance decreases until to remove the bitumen of the aggregate’s surface in contact with the vehicle’s tire. In order to improve the structural and performance properties of the porous asphalt، polymer modified binders has been frequently used during three past decades. In this research the effect of modified binders with crumb rubber made of old tires is applied in three different percentages (10%، 15% and 20% by weight binders)، evaluation on the skid resistance in the initial period operation and young and aged samples abrasion loss of porous asphalt mixtures are compared with styrene–butadiene–styrene (SBS) modified binders and AC 60/70. The results indicate that mixtures made of 10% crumb rubber modified binders have a better performance than mixtures made of (SBS) modified binders and AC 60/70.