A study of the effects of spatial contiguity and hierarchically structured headings in a shipboard operating and maintenance manual

The notion of operating and maintenance manuals being validated as fit for purpose is based largely on conjecture, as causal factors contributing to rule-based (procedure-based) human error at sea are under-theorised and under-researched. Human factors theories offer little in terms of framework as to the constitution of a bad rule. In this study, an original equipment manufacturer (OEM) operating and maintenance manual was assessed against two rule-based error-provoking markers identified through literature review. The contribution of the original and subsequently modified OEM operating and maintenance manuals towards both behaviour modification and rule-based error was assessed through a workshop-based study. Randomly selected seafaring participants were tasked with the responsibility of executing a typical shipboard operational procedure by referring to an original or modified version of the manual. The study supported the following hypotheses: (1) the hierarchical access structure of headings in an operating and maintenance manual supports the primary function of selection, and (2) the efficacy of inference in a procedure-based task is dependent upon the spatial contiguity of corresponding text and illustrations in an operating and maintenance manual. The findings of this study suggest that a nexus exists between the structure of operating and maintenance manuals, behaviour modification and human error. Furthermore, this study demonstrates a need for further research into specific causal factors contributing towards rule-based error in shipboard operating and maintenance tasks.     

Dependability as a measure of on-time performance of personal rapid transit systems

A comprehensive method for calculating and measuring Dependability of Personal Rapid Transit systems is derived and compared with the more common measure called Availability. Availability is the percentage of all revenue trips that are completed without interruption. It does not take into account the duration of delays of the passengers because of the diffiiculty of gathering the necessary information in conventional transit systems. In PRT systems, vehicle-hours of travel and of delay relate in a statistically simple way to person-hours of travel and of delay. Therefore, in such systems, it is practical to use the performance measure called Dependability that takes into account the inconveince of people as a result of delays. To form a bridge to present practice, it is recommended that both measures be calculated and compared in forthcoming PRT systems. With today's computer systems, this is easily accomplished.     

Quantitative assessment of effect of enforcement intensity on violation rates of vehicle weight and dimension regulations

A theory of upper bound limit describing the relationship between maximum possible violation rate as a function of the intensity of enforcement of vehicle weight and dimension regulations and indeed other transport administrative regulations is postulated. The model is an exponential function that determines the maximum violation rate for given inspection capacity. The constant of the function depends on the method of enforcement. The theory is demonstrated to be valid. It has potential for facilitating important policy issues relating to enforcement of transport administrative regulations and within the framework of infrastructure management to be addressed.

The relative effectiveness of enforcement methods is quantified by two parameters namely, the effectiveness index and the truckers’ relative perceived probability of detection. These parameters facilitate evaluation of the performance of various enforcement methods and operation strategies. It is found that patrol teams are, on average, 30 times as effective in detecting violations as continuously operated permanent weigh scales. High perceived detection probabilities are associated with high inspection capacities. To increase the perceived detection probability (reduce violation rates) therefore implies increasing the inspection capacity.     

Mass transportation needs and financing in the United States

The U.S. Department of Transportation (1974) recently completed a comprehensive study of mass transportation needs and methods for financing these needs. Using information from the 1974 National Transportation Study, the study determined the level of capital and operating funds that would be required to implement the 1972–90 long-range plans and 1972–80 short-range programs of the states and urbanized areas. It then analyzed various funding mechanisms at state and local levels for financing their portions of these plans and programs.It was found that urban areas, in general, not only plan to stabilize transit fares in the face of rising costs, but also intend to put $ 23.6 billion into capital investments through 1980 and an additional $ 34.6 billion through 1990. Of the total $ 58.2 billion in capital expenditures by 1990, 63% would be expended by the nine largest urbanized areas; 27.8% by the New York area alone. Rail transit and commuter railroad costs would account for 90% of the nine largest urbanized areas.States and localities would be able to carry the financial burden of mass transportation improvements, even if the proposed 1980 programs were implemented in their entirety, given current levels of Federal assistance. However, there would have to be a substantial financial commitment from the states and localities and some hard decisions made by them about public expenditure priorities, fare policies, and taxation levels, and policies to discourage automobile usage. This underscores the need for careful review of their overall plans and programs by state and local officials before making financial commitments.     

Redefinition of roles and responsibilities in U.S. transportation

Major shifts in U.S. Federal transportation policy are occurring which are realigning the roles and responsibilities of the Federal, State and local governments, and the private sector. These shifts include a decentralization of control to State and local governments, a larger role for the private sector, and reduced emphasis on construction of new facilities and more on rehabilitation and utilization of existing facilities. Although some reaction to these changes is already apparent, it is unclear at this time what the effect will be on improving the efficiency and effectiveness of transportation systems.     

Forecasting downtime event durations for the Morgantown people mover

A model was developed to forecast the duration of emergency shut downs of the Morgantown People Mover. An extensive data base of downtime events for a 2 1/2 year period were analyzed. Analysis of Variance (ANOVA) methods were applied to determine the significance of five variables which were hypothesized to influence downtime duration, including physical sub-system, restartablity, location of failure, number of vehicles in the system, and level of demand. Results of the analysis enable MPM system operators to provide improved information to system users during downtime events. The forecasting methodology also enables operators to evaluate alternative user management strategies during downtimes.     

A continuum model for the dispersion of traffic on two-lane roads

A continuum model for two-lane traffic flow is developed using the theory of kinematic waves in which the wavespeeds in the two lanes are assumed constant but unequal. The transient behaviour is found exactly using Riemann's method of characteristics and an asymptotic model of the long time flow is described. It is shown, that for large times, the traffic concentration moves with a weighted mean wavespeed of the two lanes and disperses about this mean speed as a result of interlane concentration differences generated by the relative wavespeeds. The dispersion can be described by a virtual coefficient of diffusion proportional to the square of the differences of the two wavespeeds and inversely proportional to the rate of lane changing. The technique is extended to describe three-lane traffic flow and to include the dependence of wavespeed upon concentration.