Microscopic modelling of freeway operations

Freeways are divided roadways designed to facilitate the uninterrupted movement of motor vehicles. However, many freeways now experience demand flows in excess of capacity, leading to recurrent congestion. The Highway Capacity Manual (TRB, 1994) uses empirical macroscopic relationships between speed, flow and density to quantify freeway operations and performance. Capacity may be predicted as the maximum uncongested flow achievable. Although they are effective tools for design and analysis, macroscopic models lack an understanding of the nature of processes taking place in the system. Szwed and Smith (1972, 1974) and Makigami and Matsuo (1990) have shown that microscopic modelling is also applicable to freeway operations. Such models facilitate an understanding of the processes whilst providing for the assessment of performance, through measures of capacity and delay. However, these models are limited to only a few circumstances. The aim of this study was to produce more comprehensive and practical microscopic models. These models were required to accurately portray the mechanisms of freeway operations at the specific locations under consideration. The models needed to be able to be calibrated using data acquired at these locations. The output of the models needed to be able to be validated with data acquired at these sites. Therefore, the outputs should be truly descriptive of the performance of the facility. A theoretical basis needed to underlie the form of these models, rather than empiricism, which is the case for the macroscopic models currently used. And the models needed to be adaptable to variable operating conditions, so that they may be applied, where possible, to other similar systems and facilities. It was not possible to produce a stand-alone model which is applicable to all facilities and locations, in this single study, however the scene has been set for the application of the models to a much broader range of operating conditions. Opportunities for further development of the models were identified, and procedures provided for the calibration and validation of the models to a wide range of conditions. The models developed, do however, have limitations in their applicability. Only uncongested operations were studied and represented. Driver behaviour in Brisbane was applied to the models. Different mechanisms are likely in other locations due to variability in road rules and driving cultures. Not all manoeuvres evident were modelled. Some unusual manoeuvres were considered unwarranted to model. However the models developed contain the principal processes of freeway operations, merging and lane changing. Gap acceptance theory was applied to these critical operations to assess freeway performance. Gap acceptance theory was found to be applicable to merging, however the major stream, the kerb lane traffic, exercises only a limited priority over the minor stream, the on-ramp traffic. Theory was established to account for this activity. Kerb lane drivers were also found to change to the median lane where possible, to assist coincident mergers. The net limited priority model accounts for this by predicting a reduced major stream flow rate, which excludes lane changers. Cowan's M3 model as calibrated for both streams. On-ramp and total upstream flow are required as input. Relationships between proportion of headways greater than 1 s and flow differed for on-ramps where traffic leaves signalised intersections and unsignalised intersections. Constant departure onramp metering was also modelled. Minimum follow-on times of 1 to 1.2 s were calibrated. Critical gaps were shown to lie between the minimum follow-on time, and the sum of the minimum follow-on time and the 1 s minimum headway. Limited priority capacity and other boundary relationships were established by Troutbeck (1995). The minimum average minor stream delay and corresponding proportion of drivers delayed were quantified theoretically in this study. A simulation model was constructed to predict intermediate minor and major stream delays across all minor and major stream flows. Pseudo-empirical relationships were established to predict average delays. Major stream average delays are limited to 0.5 s, insignificant compared with minor stream delay, which reach infinity at capacity. Minor stream delays were shown to be less when unsignalised intersections are located upstream of on-ramps than signalised intersections, and less still when ramp metering is installed. Smaller delays correspond to improved merge area performance. A more tangible performance measure, the distribution of distances required to merge, was established by including design speeds. This distribution can be measured to validate the model. Merging probabilities can be predicted for given taper lengths, a most useful performance measure. This model was also shown to be applicable to lane changing. Tolerable limits to merging probabilities require calibration. From these, practical capacities can be estimated. Further calibration is required of traffic inputs, critical gap and minimum follow-on time, for both merging and lane changing. A general relationship to predict proportion of drivers delayed requires development. These models can then be used to complement existing macroscopic models to assess performance, and provide further insight into the nature of operations.

The dynamics and performance of the building and construction product system

During 1999 the Department of Industry, Science and Resources (ISR) published 4 research reports it had commissioned from the Australian Expert Group in Industry Studies (AEGIS), a research centre of the University of Western Sydney, Macarthur. ISR will shortly publish the fifth and final report in this series. The five reports were commissioned by the Department, as part of the Building and Construction Action Agenda process, to investigate the dynamics and performance of the sector, particularly in relation its innovative capacity. Professor Jane Marceau, PVCR at the University of Western Sydney and Director of AEGIS, led the research team. Dr Karen Manley was the researcher and joint author on three of the five reports. This paper outlines the approach and key findings of each of the five reports. The reports examined 5 key elements of the ‘building and construction product system’. The term ‘product system’ reflects the very broad range of industries and players we consider to contribute to the performance of the building and construction industries. The term ‘product system’ also highlights our focus on the systemic qualities of the building and construction industries. We were most interested in the inter-relationships between key segments and players and how these impacted on the innovation potential of the product system. The ‘building and construction product system’ is hereafter referred to as ‘the industry’ for ease of presentation. All the reports are based, at least in part, on an interviewing or survey research phase which involved gathering data from public and private sector players nationally. The first report ‘maps’ the industry to identify and describe its key elements and the inter-relationships between them. The second report focuses specifically on the linkages between public-sector research organisations and firms in the industry. The third report examines the conditions surrounding the emergence of new businesses in the industry. The fourth report examines how manufacturing businesses are responding to customer demands for ‘total solutions’ to their building and construction needs, by providing various services to clients. The fifth report investigates the capacity of the industry to encourage and undertake energy efficient building design and construction.

Board network characteristics and company performance in Sweden : the case of Gnosjö companies and their board members in southern Sweden

When managers of entrepreneurial companies typically talk about strategies, they first consider what products to make and secondly where to locate the business. The entrepreneurial companies locate in rural areas because of a wish to maintain a certain lifestyle, or because they can combine a resource available there with certain knowledge or interest that they have (Getz and Nilsson, 2004). In addition, many managers of entrepreneurial companies are confident in locating in a rural area, because there often is economic and social structure supportive of local corporate governance. The most central part of corporate governance is the board of directors. In an entrepreneurial company in a rural area, such members of boards are most likely to be individuals in dominant positions influential in the local economy.

Implementing an employee performance management system in a nonprofit organization

Nonprofit organizations are not exempt from the imperatives of employee attraction, retention, and motivation. As competition for staff, donors, and funding increases, the need to manage employee performance will continue to be a critical human resource management issue. This article outlines a study of the introduction of a performance management system in an Australian nonprofit organization and analyzes its design and implementation. It explores how performance management can be introduced and used effectively within a nonprofit environment to benefit staff and the organization. However, the use of performance management is not without its challenges, and the research also identified initial employee resistance and a resulting initial spike in labor turnover. However, findings indicate that if nonprofit organizations are willing to undertake consultation with staff and ensure that the organization's specific context, values, and mission are reflected in the performance management system, it can be a useful tool for managers and a direct benefit to employees.

Technology strategy and competitive performance : A study of bridge construction

Doctoral dissertation, Stanford University, California, 1993

Strategies for appropriate technology and competitive performance in infrastructure construction

Earlier research developed theoretically-based aggregate metrics for technology strategy and used them to analyze California bridge construction firms (Hampson, 1993). Determinants of firm performance, including trend in contract awards, market share and contract awards per employee, were used as indicators for competitive performance. The results of this research were a series of refined theoretically-based measures for technology strategy and a demonstrated positive relationship between technology strategy and competitive performance within the bridge construction sector. This research showed that three technology strategy dimensions—competitive positioning, depth of technology strategy, and organizational fit— show very strong correlation with the competitive performance indicators of absolute growth in contract awards, and contract awards per employee. Both researchers and industry professionals need improved understanding of how technology affects results, and how to better target investments to improve competitive performance in particular industry sectors. This paper builds on the previous research findings by evaluating the strategic fit of firms' approach to technology with industry segment characteristics. It begins with a brief overview of the background regarding technology strategy. The major sections of the paper describe niches and firms in an example infrastructure construction market, analyze appropriate technology strategies, and describe managerial actions to implement these strategies and support the business objectives of the firm.

A comprehensive investigation into the hydrodynamic and capture/retention performance of a gross pollutant trap

A novel and comprehensive testing approach to examine the performance of gross pollutant traps (GPTs) was developed. A proprietary GPT with internal screens for capturing gross pollutants—organic matter and anthropogenic litter—was used as a case study. This work is the first investigation of its kind and provides valuable practical information for the design, selection and operation of GPTs and also the management of street waste in an urban environment. It used a combination of physical and theoretical models to examine in detail the hydrodynamic and capture/retention characteristics of the GPT. The results showed that the GPT operated efficiently until at least 68% of the screens were blocked, particularly at high flow rates. At lower flow rates, the high capture/retention performance trend was reversed. It was also found that a raised inlet GPT offered a better capture/retention performance. This finding indicates that cleaning operations could be more effectively planned in conjunction with the deterioration in GPT’s capture/retention performance.

Note sequence morphing algorithms for performance of electronic dance music

This paper describes algorithms that can musically augment the realtime performance of electronic dance music by generating new musical material by morphing. Note sequence morphing involves the algorithmic generation of music that smoothly transitions between two existing musical segments. The potential of musical morphing in electronic dance music is outlined and previous research is summarised; including discussions of relevant music theoretic and algorithmic concepts. An outline and explanation is provided of a novel Markov morphing process that uses similarity measures to construct transition matrices. The paper reports on a ‘focus-concert’ study used to evaluate this morphing algorithm and to compare its output with performances from a professional DJ. Discussions of this trial include reflections on some of the aesthetic characteristics of note sequence morphing. The research suggests that the proposed morphing technique could be effectively used in some electronic dance music contexts.

The art of careful listening : children as co-artists in the making of live performance

Since 2007 Kite Arts Education Program (KITE), based at Queensland Performing Arts Centre (QPAC), has been engaged in delivering a series of theatre-based experiences for children in low socio-economic primary schools in Queensland. The twelve-week workshop experience culminates in a performance developed by the children with the assistance of the teacher artists from KITE for their community and parents/carers in a peak community cultural institution. Using Wartella’s notion of the socially competent child this analysis interrogates the performance product Precious, child participation modes, the intersection between the professional artists, teacher artists and child artists and outcomes in terms of building capacities for the development of social competencies in children.

Review of the under the limit drink driving rehabilitation program

The combination of alcohol and driving is a major health and economic burden to most communities in industrialised countries. The total cost of crashes for Australia in 1996 was estimated at approximately 15 billion dollars and the costs for fatal crashes were about 3 billion dollars (BTE, 2000). According to the Bureau of Infrastructure, Transport and Regional Development and Local Government (2009; BITRDLG) the overall cost of road fatality crashes for 2006 $3.87 billion, with a single fatal crash costing an estimated $2.67 million. A major contributing factor to crashes involving serious injury is alcohol intoxication while driving. It is a well documented fact that consumption of liquor impairs judgment of speed, distance and increases involvement in higher risk behaviours (Waller, Hansen, Stutts, & Popkin, 1986a; Waller et al., 1986b). Waller et al. (1986a; b) asserts that liquor impairs psychomotor function and therefore renders the driver impaired in a crisis situation. This impairment includes; vision (degraded), information processing (slowed), steering, and performing two tasks at once in congested traffic (Moskowitz & Burns, 1990). As BAC levels increase the risk of crashing and fatality increase exponentially (Department of Transport and Main Roads, 2009; DTMR). According to Compton et al. (2002) as cited in the Department of Transport and Main Roads (2009), crash risk based on probability, is five times higher when the BAC is 0.10 compared to a BAC of 0.00. The type of injury patterns sustained also tends to be more severe when liquor is involved, especially with injuries to the brain (Waller et al., 1986b). Single and Rohl (1997) reported that 30% of all fatal crashes in Australia where alcohol involvement was known were associated with Breadth Analysis Content (BAC) above the legal limit of 0.05gms/100ml. Alcohol related crashes therefore contributes to a third of the total cost of fatal crashes (i.e. $1 billion annually) and crashes where alcohol is involved are more likely to result in death or serious injury (ARRB Transport Research, 1999). It is a major concern that a drug capable of impairment such as is the most available and popular drug in Australia (Australian Institute of Health and Welfare, 2007; AIHW). According to the AIHW (2007) 89.9% of the approximately 25,000 Australians over the age of 14 surveyed had consumed at some point in time, and 82.9% had consumed liquor in the previous year. This study found that 12.1% of individuals admitted to driving a motor vehicle whilst intoxicated. In general males consumed more liquor in all age groups. In Queensland there were 21503 road crashes in 2001, involving 324 fatalities and the largest contributing factor was alcohol and or drugs (Road Traffic Report, 2001). 23438 road crashes in 2004, involving 289 fatalities and the largest contributing factor was alcohol and or drugs (DTMR, 2009). Although a number of measures such as random breath testing have been effective in reducing the road toll (Watson, Fraine & Mitchell, 1995) the recidivist drink driver remains a serious problem. These findings were later supported with research by Leal, King, and Lewis (2006). This Queensland study found that of the 24661 drink drivers intercepted in 2004, 3679 (14.9%) were recidivists with multiple drink driving convictions in the previous three years covered (Leal et al., 2006). The legal definition of the term “recidivist” is consistent with the Transport Operations (Road Use Management) Act (1995) and is assigned to individuals who have been charged with multiple drink driving offences in the previous five years. In Australia relatively little attention has been given to prevention programs that target high-risk repeat drink drivers. However, over the last ten years a rehabilitation program specifically designed to reduce recidivism among repeat drink drivers has been operating in Queensland. The program, formally known as the “Under the Limit” drink driving rehabilitation program (UTL) was designed and implemented by the research team at the Centre for Accident Research and Road Safety in Queensland with funding from the Federal Office of Road Safety and the Institute of Criminology (see Sheehan, Schonfeld & Davey, 1995). By 2009 over 8500 drink-drivering offenders had been referred to the program (Australian Institute of Crime, 2009).

The gender diversity-performance relationship in services and manufacturing organizations

Empirical findings on the link between gender diversity and performance have been inconsistent. This paper presents three competing predictions of the organizational gender diversity-performance relationship: a positive linear prediction derived from the resource-based view of the firm, a negative linear prediction derived from self-categorization and social identity theories, and an inverted U-shaped curvilinear prediction derived from the integration of the resource-based view of the firm with self-categorization and social identity theories. This paper also proposes a moderating effect of industry type (services vs. manufacturing) on the gender diversity-performance relationship. The predictions were tested in publicly listed Australian organizations using archival quantitative data with a longitudinal research design. The results show partial support for the positive linear and inverted U-shaped curvilinear predictions as well as for the proposed moderating effect of industry type. The curvilinear relationship indicates that different proportions of organizational gender diversity have different effects on organizational performance, which may be attributed to different dynamics as suggested by the resource-based view and self-categorization and social identity theories. The results help reconcile the inconsistent findings of past research that focused on the linear gender diversity-performance relationship. The findings also show that industry context can strengthen or weaken the effects of organizational gender diversity on performance.

For the better or the worse? The impact of business idea changes on new venture performance and novelty

Should new ventures stick to their knitting once they start commercialising or should they engage in frequent changes of their business idea? In this paper we argue that new ventures still need to learn their way in the early phases of commercialisation and that changes are good, but subject to two important contingencies. First is that changes should be aimed at enhancing uniqueness, which in turn enhances new venture performance. Second is that our results show that changes have limited affect on uniqueness and performance for entrepreneurs aiming at maximising opportunities, but that changing the business idea has a significant positive impact for entrepreneurs focusing on minimising losses. Our findings indicate that entrepreneurs aiming at minimising losses may offset their initial disadvantages by engaging in a series of adaptations of the business idea to gain higher performance and a more unique product offering.

Do programs to improve business performance in small and medium manufacturing enterprise improve opportunity recognition?

Increasing awareness of the benefits of stimulating entrepreneurial behaviour in small and medium enterprises has fostered strong interest in innovation programs. Recently many western countries have invested in design innovation for better firm performance. This research presents some early findings from a study of companies which participated in an holistic approach to design innovation, where the outcomes include better business performance and better market positioning in global markets. Preliminary findings from in-depth semi-structured interviews indicate the importance of firm openness to new ways of working and developing new processes of strategic entrepreneurship. Implications for theory and practice are discussed.

The role of digressive learning and uniqueness on performance : longitudinal evidence from young firms

The ability to differentiate from competitors through the selection of unique offerings is an important cornerstone of competitive performance. Developing unique products and services to offer in the marketplace is not only important for established firms, but also an important strategic choice for young firms (Baum and Haveman, 1997). Unlike large and established firms, young firms tend to have less access to adequate resources, well-developed sources of information, contact networks, and considerable experience and management know-how. That is, these firms differ significantly in their attributes and performance from larger and well-established firms (c.f. Miller and Chen, 1994). Although young firms are disadvantaged by the paucity of resources in putting together its unique product offering(s), they develop different pathways in advancing their assortment of capabilities that enables them to stay ahead of competitors.

Nascent venture performance : linking novelty of venture ideas and commitment of firm founders as predictors

The individual-opportunity nexus emphasizes that both the characteristics of individuals and venture ideas have roles in the entrepreneurial process (Shane & Venkataraman, 2000). Following upon this assertion the present study examined whether the venture idea novelty and investment of resources can make an important part in the venture creation process. Data analysed for a sample of nascent entrepreneurs in Australia suggests that the novelty of venture ideas restricts the performance of nascent ventures. However, the more investment of time and money do not show a significant impact to the venture performance.