Search

In this paper, research is done in the influence of different terrain and traffic conditions on road sections on the driver?s driving performances, i.e. on the car energy efficiency and CO2 emission. A methodology aimed at determining to which extent unfavorable traffic and/or terrain conditions on a road section contribute to the driver?s worse driving performances, and also to determine when the driver?s aggressive driving style is responsible for greater fuel consumption and greater CO2 emission is proposed. In order to apply the proposed methodology, a research study was carried out in a cargo transportation company and 12 drives who drove the same vehicle on five different road sections were selected. As many as 284014 of the instances of the data about the defined parameters of the road section and the driver?s driving style were collected, based on which and with the help of machine learning a prediction of the scores for the road section and the scores for the driver?s driving style was performed. The obtained results have shown that the proposed methodology is a useful tool for managers enabling them to simply and quickly determine potential room for increasing the energy efficiency of the vehicle fleet and decreasing CO2 emission.

This paper analyzes the effects of intercity bus suspension system oscillatory parameters on driver?s ride comfort and road damage. The analysis has been carried out through simulation by means of validated in-plane bus model with six degrees of freedom ex-cited by real road roughness signal. Low root-mean-square values of the weighted vertical acceleration (less than 0.315 m/s2) have been achieved by shock-absorbers with lower damping coefficient and softer suspension system springs. Low values of dynamic load coefficient provide low shock-absorber damping and softer springs. However, low crest factor values for both axles are accomplished for high shock-absorber damping and softer springs in bus suspension system. Results from this analysis could be used as reference for selecting proper oscillatory parameter values when designing road-friendly bus suspension system which in turn would increase vehicle energy efficiency. Presented methods, results and analyzes are the part of wider methodology for assessing the impact of bus suspension system on fuel consumption and CO2 emission.

The efficient vehicle procurement is an important business segment of different companies with their own vehicle fleet. It has a significant influence on reducing transport and maintenance costs and on increasing the fleet&rsquo, s energy efficiency. It is indispensable that managers consider various criteria from several aspects when procuring a vehicle. In that sense, we defined 13 relevant criteria and divided them into four multidisciplinary aspects: Construction-technical, financial, operational, and environmental. Decision-Making Trial and Evaluation Laboratory-Based Analytic Network Process (DANP) method was applied to evaluate the significance of defined criteria and aspects and their interdependency. It is established that the three most important criteria for vehicle procurement are vehicle price, vehicle maintenance, and vehicle selling price. The most important aspect is construction technical aspect, while the aspect of the environment is the least important. The technique for Order Preference by Similarity to Ideal Solution (TOPSIS) method was used to rank eight different vehicles, which were considered by vehicle fleet manager at the observed company. This model assists fleet managers in the selection of the most suitable vehicle for procurement, while significantly reducing decision-making time and simultaneously observing all necessary criteria and their weights. Moreover, we have considered 10 different scenarios to establish whether and how the rank of the observed alternatives would change.

Integrated fleet maintenance management represents implementation of measures, actions and decision making with the aim of decreasing total maintenance costs and increasing energy efficiency fulfilling requirements of three interdependent components: transport, maintenance and their environment. Therefore, a methodology for integrated fleet maintenance management is developed and presented in this paper. The purpose of the methodology is to contribute in increasing fleet’s energy efficiency and evaluate managers’ fleet maintenance management efficiency. The methodology was implemented in the company with own light and medium goods vehicle fleet. According to realized values of defined indicators, the maintenance management has become more efficient in the observed period. It contributed to specific fuel consumption reduction per transport volume, thereby increasing fleet’s energy efficiency. Further, the fleet size was reduced, which affected the rational realization of the given transport volume in the observed period. [Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. 36010: Development of the Model for Managing the Vehicle Technical Condition in Order to Increase its Energy Efficiency and Reduce Exhaust Emissions]

In this paper is researched how to achieve an effective fleet maintenance planning in transport companies, which contributes in increasing the fleet energy efficiency and in achieving the companies’ goal. Within the fleet maintenance planning, managers have to make the right decisions on the selection of vehicle service centers in the region where the maintenance work will be realized. The mentioned decision is affected by a number of different interdependent factors (criteria). Based on a survey, relevant factors (criteria) were defined. As defined factors are interdependent and differently influence the mentioned decision, an approach of decision making trial and evaluation laboratory (DEMATEL)-based analytic network process called DANP was applied. In this respect, authors propose a hybrid multi-criteria decision making model. The proposed model was applied in the companies to demonstrate how effective their managers are in the maintenance planning and how this effectiveness influences the fleet energy efficiency and fulfilment of companies’ goal. [Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. 36027: Software development and national database for strategic management and development of transportation means and infrastructure in road, rail, air and inland waterways transport using the European transport network models]

Companies with own vehicle fleet for freight transport try to carry out the requested transport volume, with lowest possible transportation and maintenance costs. In order to make energy efficient and rational, the vehicle fleet operation the influence of the maintenance management has been considered in this paper. In this sense, a concept of maintenance management with a comprehensive approach has been developed. Within proposed concept the interdependent influences between vehicle maintenance process, transport process and environment as well have been described in detail, and the maintenance management activities on the strategical, tactical and operational level have been presented. The proposed concept was implemented in a company with vehicle fleet. Improvements were made in the vehicle fleet operation, which contributed to the reduction of transport and maintenance costs, whereby the requested transport volume in the observed period was performed.