Comparative Analysis on Road Users’Cost Using HDM-4 Software and Manual Technique:A Case of Addis Ababa-Adama Expressway

Continuous changes in vehicle technology,road condition,traffic compo­sitions initiate the change or updating of road users’cost models.So that it needs to practice a continuous revision or update periodically for realistic estimation of costs and benefits.This paper presented the relationship and comparison between road users’cost along Addis Ababa-Adama newly constructed expressway using the Highway Development and Management(HDM-4)Software and manually using formulations developed in the Por­tuguese model.The method started with data collection.All input data were collected from primary and secondary sources.The primary data utilized an interview,and secondary data were sourced out from pertinent documents,both published and unpublished.More data were gathered that related to vehicles.The vehicles using the road are classified based on the manual from the Ethiopian Road Authority as cars,utilities,small bus,large bus,small truck,medium truck,heavy truck,and truck trailer.The collected data have been input into the HDM-4 interface;the output of the analysis was vehicle operating costs,travel time,and road users’cost as a summation.Using manual technique and HDM-4 Software,Birr 128.62/km/vehicle and Birr 139.23/km/vehicle,respectively,were found from road users’costs analysis.The result shows the difference of Birr 10.61.Also,the correlation coefficient of 0.75 is determined,which shows that the two results of road users’costs are highly related.As a result,the study reveals that the appli­cation of HDM-4 Software and the manual technique formulations from the Portuguese model can be adopted interchangeably to calculate Road Users’Cost of road sections in Ethiopia.Hence,the study results are expected to be an eye-opener for a future similar project by the concerned agencies.

Making Data-Driven Transportation Decisions for Freight Operations

Using Louisiana’s Interstate system, this paper aims to demonstrate how data can be used to evaluate freight movement reliability, economy, and safety of truck freight operations to improve decision-making. Data mainly from the National Performance Management Research Data Set (NPMRDS) and the Louisiana Crash Database were used to analyze Truck Travel Time Reliability Index, commercial vehicle User Delay Costs, and commercial vehicle safety. The results indicate that while Louisiana’s Interstate system remained reliable over the years, some segments were found to be unreliable, which were annually less than 12% of the state’s Interstate system mileage. The User Delay Costs by commercial vehicles on these unreliable segments were, on average, 65.45% of the User Delay Cost by all vehicles on the Interstate highway system between 2016 and 2019, 53.10% between 2020 and 2021, and 70.36% in 2022, which are considerably high. These disproportionate ratios indicate the economic impact of the unreliability of the Interstate system on commercial vehicle operations. Additionally, though the annual crash frequencies remained relatively constant, an increasing proportion of commercial vehicles are involved in crashes, with segments (mileposts) that have high crash frequencies seeming to correspond with locations with recurring congestion on the Interstate highway system. The study highlights the potential of using data to identify areas that need improvement in transportation systems to support better decision-making.

China＇s Housing Market Imbalance from 2003 to 2016： An Analysis Based on the User Cost Approach

During 2003-2016, China experienced an unprecedented housing market imbalance. The present paper applies the user cost approach to conduct a systematic analysis of this important phenomenon, examines the policy factors behind the persistent housing market imbalance, and explores policy options to correct the housing market imbalance. We found that during most of 2003-2016, the user cost was significantly lower than 2 percent, caused by high income growth, rapid credit expansion and low interest rates, which led to the persistent housing market imbalance. Therefore, the government should control bank credit and introduce property taxes during the possession of houses.

Security Analysis Model, System Architecture and Relational Model of Enterprise Cloud Services

Cloud computing is one of the fastest growing and popular computer technologies, and there are more and more enterprise services based on the cloud computing. In order to save costs, more and more enterprises and their employees have hired the enterprise cloud services, and put much important information in the cloud gradually. Cloud service systems have become the main targets of malicious attacks. However, the cloud computing technologies are still not perfect, and the management and maintenance of enterprise cloud services are more complex compared to traditional network services of cloud computing. So, enterprise cloud services are more likely to encounter some security problems, and the influenced scale of these security problems is broad. But there are few researches on the security of enterprise cloud services. In this paper, we analyze the software as a service（Saa S） enterprise cloud services and introduce the research status of security problems in cloud computing environment. Combining with the analysis of the characteristics and application architecture of Saa S enterprise cloud services, we propose the security problems analysis model, the analysis system architecture and the relational model. Our researches can support further research of the automatic generation of solutions and guide the deployment of security policies of Saa S enterprise cloud services.