Thesis (Ph. D.)--University of New South Wales, 2006. / Title from PDF title page (viewed on Dec. 11, 2007). Includes bibliographical references (p. 179-201).

<p>Nowadays, NRTS (Nighttime Road Traffic Safety) and energy saving are very hot topics in transportation field. This thesis investigates a general optimal model for minimizing NRTAs (nighttime road traffic accidents) and power consumption of the road lighting. To establish this model, the relationship between N/D RTAs (Night to Day Road Traffic Accidents) ratio and road lighting condition and the relationship between power consumption and road lighting condition have been studied and explained. A media variable “economic cost” has been chosen which is used for making a connection between these two relationships. The evaluations of NRTAs and power consumption from cost point of view are introduced as well. The impacts of each internal factor defined by author are explained carefully. The result of the model based on these relationships and internal influencing factors is presented in the paper. Finally, the recommendations for reducing NRTAs and/or power consumption, as well as other interesting areas for further study are presented.</p>

<p>Several cities have implemented various projects to improve traffic safety in city centers.During 1970s and 1980s the city centers changed as the suburbs grew and large shopping centers were located outside the center. At the same time, several projects were initiated with construction of pedestrian streets and restriction of traffic in the center. In year 1994,shared-used areas were introduced in Sweden and these areas are often used in center environments.</p><p>In Sweden, municipalities are responsible for integrating security in public places and in comprehensive plans and detailed development plans. The National Board of Housing,Building and Planning is the authority for administrating planning issues and develop general guidance about planning. Traffic is one of their key issues, although today there are no concrete guidelines from the National Board of Housing, Building and Planningfor the design of traffic safety in city centers.</p><p>Traffic safety in city centers affects many people because the city center is a public place.It is therefore important that there are current guidelines available that are helpful for changes and improvements in traffic safety in the city center.</p><p>The purpose of this report is to formulate guidelines for planning city centers from a traffic safety perspective. The aim is that the guidelines can be applied in the design of smaller city centers for improving traffic safety. For this report two case studies were implemented that included inventories and observations of Bollnäs and Sandviken city centers. The results showed that many of the streets did not function well and that there was a lack of design in the city centre center from a traffic safety perspective, for example pedestrian crossings and car parks.</p><p>Inventories and observations are good methods to see how the traffic environment in the city center varies in use and function. The observations and inventories resulted in guidelines with recommendations for the design of streets and traffic in small city centers.</p> / <p>Flera städer har genomfört olika projekt för att öka trafiksäkerheten i stadscentrumen.Under 1970-talet och 1980-talet förändrades stadscentrum i takt med att förorter växte fram och externa köpcentrum etablerades utanför centrum. Samtidigt påbörjades flera projekt med att anlägga gågator och begränsa biltrafiken i centrum. År 1994 infördes gårdsgator i Sverige och dessa används ofta i centrummiljöer.</p><p>I Sverige är det kommunerna som ansvarar för att säkerhet integreras planering av offentliga platser. Boverket är den myndighet som förvaltar frågor och tar fram allmänna råd angående planering. Trafik är en av deras viktigaste planeringsfrågor men idag finns inga konkreta råd från Boverket för utformning av trafiksäkra centrum.</p><p>Trafiksäkerhet i stadscentrum påverkar många människor eftersom att centrum är enoffentlig plats. Därför är det viktigt att det finns aktuella riktlinjer som är till hjälp vid förändringar och förbättringar i trafiksäkerheten i centrum.</p><p>Rapportens syfte var att utforma riktlinjer för planering av mindre stadscentrum ur ett trafiksäkerhetsperspektiv. För att kunna upprätta riktlinjer genomfördes två fallstudier.Dessa innefattade inventering och observation av Bollnäs och Sandvikens centrum.Bollnäs och Sandvikens centrum hade liknande funktioner av gatorna. Centrumens kärna fungerade till stor del som transportsträckor men även som promenadgator. Resultaten visade att många av gatornas tänka funktioner inte fungerade och att det fanns bristandeutformning av olika målpunkter, exempelvis övergångsställen och bilparkeringar.</p><p>Inventeringar och observationer är bra metoder för att se hur trafikmiljön i centrumfungerar eftersom användning och funktion av olika målpunkter varierar.Observationerna och inventeringen resulterade i riktlinjer med rekommendationer för utformning av gator och trafikmiljö i mindre stadscentrum.</p>

A random sample of Oregon motor carriers was selected to determine the effectiveness of the Accident Countermeasures (ACM), a process created to address the factors involved in truck accidents and recommendations a motor carrier may utilize to prevent future similar accidents from occurring. Two groups of fifty motor carriers were selected, one group with a record of no accidents in a 12 month period and a group of 50 carriers who had accidents in a 12 month period. All 100 carriers were interviewed. Half of the accident groups records were reviewed and the recommendations of the ACM were supplied to the carrier, the other half was utilized as the control group. Follow up data was collected for the following year and analysis was completed to measure the effectiveness. A total of 82 Oregon based carriers remained in the study throughout its completion. The method of multiple linear regression was utilized to determine whether any variables in the set of explanatory variables considered in this study are related to the accident rate of a company. Data indicates the effect of the Miles Per Vehicle Driven in 1994, Percent of Miles Driven in Urban and the Total Out of Service are statistically significant for the Accident Rate in 1995 for the control group and the study group. It appears however, the estimated difference is only practically significant for the Miles Per Vehicle Driven in 1994 (F=20.31, p=.0001). There is no evidence of a relationship between a trucking companies accident rate in 1995 and the Accident Counter Measures intervention program. (F=.18, p=.67) The difference between the mean accident rates for a company which received the accident counter measure intervention and a company that did not receive the accident counter measure intervention ranges from -.98 to .75 (95% Confidence Interval for the difference of means). / Graduation date: 1999

The general aim of this thesis is to present and analyse traffic safety from an ethical perspective and to explore some conceptual and normative aspects of moral responsibility. Paper I presents eight ethical problem areas that should be further analysed in relation to traffic safety. Paper II is focused on the question of who is responsible for traffic safety, taking the distribution of responsibility adopted through the Swedish policy called Vision Zero as its starting point. It is argued that a distinction should be made between backwardlooking and forward-looking responsibility and that Vision Zero should be understood in terms of this distinction. Paper III discusses responsibility ascriptions in relation to public health problems like obesity and lung cancer. It is argued that what makes discussions about who is responsible for such problems complicated is that we have two aims when ascribing responsibility to someone. First, we want responsibility ascriptions to be fair and morally justified. Second, we also want to achieve progress and solve problems through ascribing responsibility to someone. It is argued that the two aims influence debates concerning who is responsible for problems like obesity and lung cancer and that we should attempt at striking a balance that is both perceived as fair and that is efficient. Paper IV discusses two potential arguments against the suggestion that alcohol interlocks should be mandatory in all cars, namely 1) that it displaces the responsibility of individual drivers, and 2) that it constitutes a paternalistic interference with drivers. The first objection is found unconvincing, while the second only has limited bite and may be neutralized if paternalism is accepted for the sake of greater net liberty. It is argued that if technological development can make mandatory interlocks cost-efficient, the policy seems a commendable public health measure. In Paper V, the question discussed is to what extent individuals should be ascribed moral responsibility for the environmentally damaging consequences of their actions. It is argued that responsibility depends on the reasonableness of the alternatives open to an individual when acting. The lack of reasonable alternatives should reduce the degree of individual responsibility. / QC 20100831

In order to achieve sustainable long-term transport infrastructure development, there is a growing need for fast, reliable and effective methods to evaluate and predict the impact of traffic safety measures. Recognising this need, and the need for an active traffic safety approach, this thesis focuses on traffic safety assessment and prediction based on the use of safety indicators that measure the spatial and/or temporal proximity of safety critical events. The main advantage of such measures is that they occur more frequently than accidents, and therefore require relatively short periods of study to establish values that can later be used for comparison, or for accident prediction purposes. There are a number of more generally accepted safety indicators including: Time-to-Accident, Time-to-Collision, and Post-Encroachment Time. These are based on different underlying principles and measurement techniques, including both on-site subjective estimation, and objective photometric measures. A major part of the work presented in this thesis, concerns identifying the potential and limitations of the different safety indicators with regard to their validity and reliability, and practical use for safety assessment and prediction purposes. This is done in conjunction with field studies in the urban and suburban environment, at both signalised and unsignalised intersections. Results from these studies indicate that on-site observation methods provide useful quantitative and qualitative information relatively quickly and efficiently, provided that they are used correctly. On the other hand, the methods based on photometric measurement (video-analysis) proved arduous and time-consuming. Furthermore, there are questions regarding the abilities of the Time-to-Collision and Post-Encroachment Time safety indicators to adequately represent interaction severity, suggesting possible flaws in fundamental concepts related to construct validity. Importantly, results showed that the relationship between safety indicators and traffic accidents is complex and equivocal, where many different factors and processes can impose a significant influence on safety. This makes generalised predictive modelling a particularly difficult task for safety analysts. The potential of micro-simulation for traffic safety and performance estimation based on the use of safety indicators was investigated in the second part of this thesis. Microscopic traffic simulation has become increasingly popular among transport planners, due to the fact that it serves as a safe and flexible off-line test environment for the estimation of dynamic and complex traffic system effects. It is useful and cost-effective in relation to the evaluation of issues concerning roadway design, and technological systems that influence road-user behaviour and vehicle performance. For reasons related to modelling fidelity and data quality, simulation has seldom been used for traffic safety estimation. Simulation model development is however, undergoing rapid development and the area of ‘safety-simulation’ and is recognised as having a high potential in the field of transport planning and traffic engineering. As part of the work in this thesis, practical simulation experiments were carried out to investigate this potential, and identify limitations. Based on the data from one of the earlier studies, and knowledge regarding important safety-influencing factors and behavioural processes, one of the simulation experiments showed evidence to suggest that realistic safety critical events could be generated and measured using safety indicators in a simulation environment, without making unnecessary and unrealistic behavioural assumptions. Furthermore, a second application of this methodology revealed the safety potential of a rear-end incident-reduction function used in standard vehicle actuated signalling. While both of these simulation studies highlighted the potential of this type of approach, the need for more flexible and realistic models of interactive behavioural processes could be identified in addition to the general need for greater active research into the field of safety simulation. / QC 20100830

Several cities have implemented various projects to improve traffic safety in city centers.During 1970s and 1980s the city centers changed as the suburbs grew and large shopping centers were located outside the center. At the same time, several projects were initiated with construction of pedestrian streets and restriction of traffic in the center. In year 1994,shared-used areas were introduced in Sweden and these areas are often used in center environments. In Sweden, municipalities are responsible for integrating security in public places and in comprehensive plans and detailed development plans. The National Board of Housing,Building and Planning is the authority for administrating planning issues and develop general guidance about planning. Traffic is one of their key issues, although today there are no concrete guidelines from the National Board of Housing, Building and Planningfor the design of traffic safety in city centers. Traffic safety in city centers affects many people because the city center is a public place.It is therefore important that there are current guidelines available that are helpful for changes and improvements in traffic safety in the city center. The purpose of this report is to formulate guidelines for planning city centers from a traffic safety perspective. The aim is that the guidelines can be applied in the design of smaller city centers for improving traffic safety. For this report two case studies were implemented that included inventories and observations of Bollnäs and Sandviken city centers. The results showed that many of the streets did not function well and that there was a lack of design in the city centre center from a traffic safety perspective, for example pedestrian crossings and car parks. Inventories and observations are good methods to see how the traffic environment in the city center varies in use and function. The observations and inventories resulted in guidelines with recommendations for the design of streets and traffic in small city centers. / Flera städer har genomfört olika projekt för att öka trafiksäkerheten i stadscentrumen.Under 1970-talet och 1980-talet förändrades stadscentrum i takt med att förorter växte fram och externa köpcentrum etablerades utanför centrum. Samtidigt påbörjades flera projekt med att anlägga gågator och begränsa biltrafiken i centrum. År 1994 infördes gårdsgator i Sverige och dessa används ofta i centrummiljöer. I Sverige är det kommunerna som ansvarar för att säkerhet integreras planering av offentliga platser. Boverket är den myndighet som förvaltar frågor och tar fram allmänna råd angående planering. Trafik är en av deras viktigaste planeringsfrågor men idag finns inga konkreta råd från Boverket för utformning av trafiksäkra centrum. Trafiksäkerhet i stadscentrum påverkar många människor eftersom att centrum är enoffentlig plats. Därför är det viktigt att det finns aktuella riktlinjer som är till hjälp vid förändringar och förbättringar i trafiksäkerheten i centrum. Rapportens syfte var att utforma riktlinjer för planering av mindre stadscentrum ur ett trafiksäkerhetsperspektiv. För att kunna upprätta riktlinjer genomfördes två fallstudier.Dessa innefattade inventering och observation av Bollnäs och Sandvikens centrum.Bollnäs och Sandvikens centrum hade liknande funktioner av gatorna. Centrumens kärna fungerade till stor del som transportsträckor men även som promenadgator. Resultaten visade att många av gatornas tänka funktioner inte fungerade och att det fanns bristandeutformning av olika målpunkter, exempelvis övergångsställen och bilparkeringar. Inventeringar och observationer är bra metoder för att se hur trafikmiljön i centrumfungerar eftersom användning och funktion av olika målpunkter varierar.Observationerna och inventeringen resulterade i riktlinjer med rekommendationer för utformning av gator och trafikmiljö i mindre stadscentrum.

Cooperative traffic safety applications such as lane change or overtaking assistance have the potential to reduce the number of road fatalities. Many emerging traffic safety applications are based on IEEE 802.11p and periodic position messages, so-called cooperative awareness messages (CAM) being broadcasted by all vehicles. In Europe, ETSI defines a periodic report rate of 2 Hz for CAMs. Although a high report rate is the key to early hazard detection, the 2 Hz rate has been chosen to avoid congestion in settings where the vehicle density is high, e.g., on major highways and in urban scenarios. However, on rural roads with a limited number of communicating vehicles, a report rate of 2 Hz leads to unnecessary delay in cooperative awareness. By adapting the CAM report rate depending on the specific application and road traffic density, and by making use of the priority levels provided by the 802.11p quality of service mechanism, we show that hazards can be detected earlier and the available bandwidth is used more efficiently, while not overexploiting the network resources. / <p>©2011 IEEE. Personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution to servers or lists, or to reuse any copyrighted component of this work in other works must be obtained from the IEEE.</p><p></p><p>Category number CFP11VTF-ART; Code 87844</p>

Nowadays, NRTS (Nighttime Road Traffic Safety) and energy saving are very hot topics in transportation field. This thesis investigates a general optimal model for minimizing NRTAs (nighttime road traffic accidents) and power consumption of the road lighting. To establish this model, the relationship between N/D RTAs (Night to Day Road Traffic Accidents) ratio and road lighting condition and the relationship between power consumption and road lighting condition have been studied and explained. A media variable “economic cost” has been chosen which is used for making a connection between these two relationships. The evaluations of NRTAs and power consumption from cost point of view are introduced as well. The impacts of each internal factor defined by author are explained carefully. The result of the model based on these relationships and internal influencing factors is presented in the paper. Finally, the recommendations for reducing NRTAs and/or power consumption, as well as other interesting areas for further study are presented.

When a traffic signals malfunction monitoring unit detects a problem with a traffic signal such as the simultaneous display of green indications to conflicting movements or loss of power to some signal heads, the signal is automatically placed into flash mode as a safety precaution. Signals can have either red/red malfunction flash mode or yellow/red malfunction flash mode, and the mode cannot change by time of day or day of week. This study analyzed traffic operation at 34 instances of yellow/red malfunction flash and 9 instances of red/red malfunction flash in the Atlanta, Georgia area. Many of these instances were during high volume periods. A high level of driver confusion exists at malfunction flash intersections. The rate at which through major street drivers (i.e. those facing a flashing yellow signal) stopped exceeded 75 percent at some yellow/red flash intersections. This creates a safety hazard for other major street drivers who are not expecting vehicles to stop, and for minor street drivers who cannot tell what type of control is being presented to cross traffic or do not understand that vehicles are not required to stop when approaching a flashing yellow indication. Furthermore, high stopping rates at a flashing yellow signal eliminate many of the operational benefits that yellow/red flash is assumed to have over red/red flash. Based on the findings of this study, the use of red/red flash should be the primary flash mode and possibly used exclusively. Requiring all vehicles to stop will improve safety conditions and not have large operational impacts at intersections where a majority of major street vehicles are already stopping at a flashing yellow signal. Yellow/red flash may be an acceptable malfunction flash mode at the intersection of a very large street and a very small street, but additional measures would be required at these intersections to address potential driver confusion.