Design and evaluation of an integrated inventory and transportation system

This paper proposes the adoption of an integrated inventory and transportation system (IITS) to minimize the total costs of inventory and transportation. A non-linear programing is developed by analyzing transportation and inventory costs with one supplier and many retailers in the distribution environment. The paper compares the proposed model with the traditional approach in computing total costs with numerical data. The results indicate that the total costs can be optimized by adopting integrated programing rather than the traditional approach, along with achieving improved customer service levels. In particular, sensitivity analysis is applied to determine the performance of the IITS under various transportation costs, holding costs and shortage costs. It shows that the transportation cost per unit is most sensitive in the proposed model. In this situation, the IITS is more effective for cost saving when set-up cost, holding and shortage costs are high, but is less effective for situations involving high per-unit transportation costs.     

Improving the estimation of total and direction-based heavy-duty vehicle annual average daily traffic

Abstract

The estimation of annual average daily traffic (AADT) is an important parameter collected and maintained by all US departments of transportation. There have been many past research studies that have focused on ways to improve the estimation of AADT. This paper builds upon previous research and compares eight methods, both traditional and cluster-based methodologies, for aggregating monthly adjustment factors for heavy-duty vehicles (US Department of Transportation Federal Highway Administration (FHWA) vehicle classes 4–13). In addition to the direct comparison between the methodologies, the results from the analysis of variance show at the 95% confidence level that the four cluster-based methods produce statistically lower variance and coefficient of variation over the more traditional approaches. In addition to these findings – which are consistent with previous total volume studies – further analysis is performed to compare total heavy-duty monthly adjustment factors, both directions of traffic, with direction-based monthly adjustment factors. The final results show that the variance as well as the coefficient of variation improve on average by 25% when directional aggregate monthly adjustment factors are used instead of total direction.     

Dynamics of LRT growth: Karlsruhe since 1975

The public transport system of Karlsruhe, in particular its innovative services on jointly used heavy rail lines, has received substantial attention throughout the past 20 years. The discussion of the system and of its development has been rather limited in the past, mostly highlighting technical aspects. This paper provides an overview of the development, including the urban development, of the region and of the funding system. The ridership and financial development of the operator is documented in detail. Three case studies focus on the integration of the system development in the general political process of the region and demonstrate the limitations of the operator under its current ownership structures.     

An overview of transport in Kuwait

Abstract

Kuwait is a relatively small country located at the top of the Arabian Gulf with population in 1980 amounting to 1.355 millions. Kuwait occupies an area of approximately 17 800 square kilometres. Kuwait's main source of national income is oil export. Income from oil export and other sources has resulted in Kuwait having the highest per capita income in the world. Consequently vehicle ownership is very high and traffic is ever growing and extending. Kuwait is self‐sufficient in only a few commodities and has a shortage of local labour. This means that transport has a fundamental role to play at the national and international level for the development of Kuwait's economy.

This paper provides a brief statement of transport in Kuwait. It starts by describing Kuwait's national setting and touches on the economic and social aspects in Kuwait that have an influence on transport patterns and needs. It describes the national transport system and covers road, air, rail and ports. Urban development planning in Kuwait is described and issues related to stages of urban development planning. The Kuwait City Master Plan and new town initiatives are presented. The urban transport system in Kuwait Metropolitan Area is described. In particular the characteristics of the urban road network and public transport facilities are outlined along with recent transport planning studies and new initiatives in the urban transport system.

The paper ends with a statement on organizations involved in the transport sector in Kuwait and a note on transport finance.     

Experience in judging controversial road projects

Abstract

Road construction of all kinds, especially of urban motorways, has in recent years acquired a very bad reputation in industrialized countries. Traffic engineers are, because of their attitude, not entirely without blame for this development. With their attention glued nearly hypnotically to dimensions and technical design, considerations about the meaning and function of the construction are very often neglected, all the more since the engineers might otherwise risk their own jobs. It is, however, becoming increasingly clear that the cause of the scepticism and uneasiness prevailing in the public is the lack of a comprehensive judgement. Using a concrete example, this paper describes how decision‐making can degenerate when such judgement is omitted. Using a second example, it is then demonstrated how such a comprehensive judgement can be integrated in decision‐making from the very beginning. Such an integration sets very high methodological and procedural standards and constructive aids are offered for this purpose. It is shown that, while the substantial findings of a comprehensive judgement should be logically consistent, plausible and up to the latest standard of knowledge, the nature and intelligibility of the presentation and the preparedness for a publicly presented explanation in the form of ‘after‐care’ are of much greater importance for decision‐making in the political sphere. This ‘after‐care’ should accordingly become an indispensable component of the decision‐making process.

All those involved should become aware of the fact that a ‘positive’ result of decision‐making in the field of road construction is not a priori defined as the construction of road and a ‘negative’ one as its prevention. The actual positive result is rather the creation of a consciousness of the problem on hand, which can serve as a basis on which a decision is taken in full realization of all its consequences.     

The federal republic of Germany: the federal ministry of transport

The continued liberalization of the airline market in the European Community offers the prospect of competition in terms of price, frequency of service and many other attributes. Understanding these factors that influence passenger demand and incorporating them into a demand function poses a substantial theoretical and empirical challenge. A basis for estimating demand functions is the logit model. This paper examines the value of a logit share model in explaining how the share of airlines between airports varies as a function of measured and unmeasured attributes. It shows how demand functions are necessary for understanding a competitive market and evaluates the progress to date in identifying accurate coefficients of the logit function.     

Restructuring the Lebanese Railway and Public Transport Authority (RPTA): From losing operator to effective regulator

The Lebanese Council of Ministers has recently endorsed a plan for the reform and organization of the Land Public Transport Sector (LPTS). The plan implies a new role for the government: it would cease being just a loss-making service provider and become the planner and regulator of the sector under a new strategy. The strategy would aim at creating the enabling environment and conditions that allow and ensure the existence of sufficient, affordable and efficient transport services provided by several private-sector operators functioning under competitive conditions. Thus, the existing autonomous Railway and Public Transport Authority (RPTA) will be restructured to serve as the effective regulator, its bus operations will be corporatized (for possible eventual privatization), and all existing private sector service providers will be regulated. Following a brief overview of the problems of the sector and the components of the reform and organization plan, this paper focuses on developing options for the restructuring of the RPTA to carry out its new role.     

A structural model of the use of automobiles by households: a case study of urban Australia

Central to the development of transport energy plans are predictions of automobile use. Together with a knowledge of the fuel efficiency of the vehicle fleet, usage acts interdependently to determine the amount of fuel consumed. In this paper we develop an econometric model system at the household level which treats vehicle use, fuel cost, and vehicle fuel efficiency as functionally interdependent. The data is drawn from Wave 1 of a4‐wave panel of Sydney households. The empirical evidence provides new insights into the influences on vehicle use and sets the context for continuing research efforts.     

Traffic integration and environmental traffic management in Denmark

This paper assesses Danish experience in attempting to integrate traffic with its surroundings in existing areas. Rest and play areas, quiet roads with a 30 km/h speed limit, and major road schemes on urban shopping streets and through villages are all discussed; so too are policies seeking to create safe routes to school, the problems arising from the introduction of speed reduction measures on bus routes, and the merits of area‐wide as opposed to incremental approaches. Evaluations indicate that speed reductions to a maximum of 30 km/h are achievable on local roads, and that the quiet street approach represents a cost‐effective and popular means of achieving environmental improvements and safer, more liveable streets for residents. It is recommended as an appropriate model for Britain to follow. Incremental implementation risks being sub‐optimal in design terms but has distinct advantages in minimizing conflicts and enabling rapid implementation. Evaluations of shopping street and village schemes are incomplete but speed reductions and environmental gains have undoubtedly been achieved.