Introduction. Road traffic injuries are the eighth leading cause of death globally and the leading cause of death among young people aged 15-29. Of individuals killed or injured in road traffic injuries, a large group comprises occupants sustaining a thorax injury in frontal crashes. The elderly are particularly at risk, as they are more fragile. The evaluation of the frontal crash performance of new vehicles is normally based on barrier crash tests. Such tests are only representative of a small portion of real-life crashes, but it is not feasible to test vehicles in all real-life conditions. However, the rapid development of computers opens up possibilities for simulating whole populations of real-life crashes using so-called stochastic simulations. This opportunity leads to the aim of this thesis, which is to develop and validate a simplified, parameterized, stochastic vehicle simulation model for the evaluation of passive restraint systems in real-life frontal crashes with regard to rib fracture injuries. Methods. The work was divided into five phases. In phase one, the geometry and properties of a finite element (FE) generic vehicle buck model were developed based on data from 14 vehicles. In the second phase, a human FE model was validated for oblique frontal crashes. This human FE model was then used to represent the vehicle occupant. In the third phase, vehicle buck boundary conditions were derived based on real-life crash data from the National Automotive Sampling System (NASS) and crash test data from the Insurance Institute for Highway Safety. In phase four, a validation reference was developed by creating risk curves for rib fracture in NASS real-life crashes. Next, these risk curves were compared to the risk of rib fractures computed using the generic vehicle buck model. In the final phase, injury mechanisms in nearside oblique frontal crashes were evaluated. Results. In addition to an averaged geometry, parametric distributions for 27 vehicle and boundary condition parameters were developed as guiding properties for the stochastic model. Particular aspects of the boundary conditions such as pulse shape, pulse angle and pulse severity were analyzed in detail. The human FE model validation showed that the kinematics and rib fracture pattern in frontal oblique crashes were acceptable for this study. The validation of the complete FE generic vehicle buck model showed that the model overestimates the risk of rib fractures. However, if the reported under-prediction of rib fractures (50-70%) in the NASS data is accounted for using statistical simulations, the generic vehicle buck model accurately predicts injury risk for senior (70-year-old) occupants. The chest injury mechanisms in nearside oblique frontal crashes were found to be a combination of (I) belt and airbag loading and (II) the chest impacting the side structure. The debut of the second mechanism was found for pulse angles of about 30 degrees. Conclusion. A parameterized FE generic passenger vehicle buck model has been created and validated on a population of real life crashes in terms of rib fracture risk. With the current validation status, this model provides the possibility of developing and evaluating new passive safety systems for fragile senior occupants. Further, an injury mechanism responsible for the increased number of outboard rib fractures seen in small overlap and near-side oblique frontal impacts has been proposed and analyzed. / Vinnova Project: Real Life Safety Innovations

Motorcycle riding is rapidly increasing in popularity in Australia, attracting a much wider demographic of people than in decades past. Unfortunately, whilst the overall road toll in Australia has generally been reducing, the proportion of motorcycle-related fatalities has been rising in recent years. Further, the proportion of motorcycle-related fatalities in Australia is unacceptably high compared to other OECD countries. To reduce motorcycle-related fatalities on Australian roads, there is an urgent need to consider motorcyclists as distinct from other road users. This program of research facilitates the understanding of safety issues from a motorcyclist perspective and provides important information on factors influencing safe and unsafe rider intentions and behaviour.----- Study 1 explored what motorcyclists thought about the issues relevant to safety and to risk-taking behaviour on a motorcycle. The aim of this study was to develop a better understanding of the factors which influence on-road riding behaviour. Using the theory of planned behaviour (TPB), identity theory, social identity theory, and items based on moral norm and causal attribution theory, a set of questions was developed to guide focus group discussions with riders, police, rider trainers, and an advocacy group for motorcycle safety. Of the 43 participants in this study, only two were not motorcycle riders. This exploratory process revealed six common behaviours that most motorcyclists agreed were essential to safety or which related directly to riskier riding.----- Two behaviours were identified as being essential to rider safety by participants. The first was the necessity of being able to handle the motorcycle proficiently and skilfully. The second related to the need for riders to maintain a high level of concentration whilst riding and to stay aware of the changing road environment.----- The safety or riskiness of two other behaviours mentioned became a matter of debate amongst participants. First, some riders said that obeying the road rules was essential to their safety, whilst others reported that it was often necessary to break the road rules in order to stay safe. Second, the definition of what constituted 'riding whilst impaired' differed amongst riders. Most riders agreed that 'drinking and riding' was dangerous. However, for some, even one alcoholic drink before riding was considered dangerous, whilst others would ride after drinking provided they did not consider themselves to be over the legal BAC limit. Some riders stated that riding when they were tired was dangerous; however, fatigue was not considered a serious safety issue for many participants.----- Two further behaviours identified by participants were often associated with their accounts of crash involvement, yet not seen as intrinsically 'unsafe' by most riders. The first of these was the concept of 'pushing your limits'. Most riders interviewed appeared to enjoy pushing the limits of their ability on a motorcycle. Whilst agreeing that pushing the limits too far was dangerous, pushing them to a point that tested a rider's abilities was often reported to facilitate safety as this process developed a rider's skill. The second behaviour that was often mentioned in connection with crashes was extreme riding (e.g., performing stunts and riding at extreme speeds). The act of perfecting a stunt was often reported to result in the crashing of the motorcycle; although, these crashes were usually accepted as a normal part of the learning process. Once perfected, performing stunts did not appear to be considered an intrinsically unsafe behaviour; unless performed in traffic or other unpredictable situations. A sizable minority of both male and female participants reported riding at extreme speeds. These riders often argued that they could ride extremely fast, safely, on public roads provided certain conditions were met (e.g., good visibility, weather, road, and motorcycle maintenance).----- Study 2 [n = 229] operationalised the six behaviours discussed above into three 'safer' behavioural intentions (i.e., handle the motorcycle skilfully, maintain 100% awareness, not ride impaired) and three 'riskier' intentions (i.e., bend road rules, push the limits, perform stunts or ride at extreme speeds). A seventh item was added to provide a global measure of a rider's intention to ride safely. Multiple regression analyses were then performed to test the predictive utility of the TPB compared with several augmented models. The additional constructs used to augment the TPB included a specific subjective norm and group norm which related to the people a person rides with, self identity, sensation seeking, aggression as well as age, gender and riding exposure. The multiple regression analysis demonstrated that a greater proportion of variance could be explained in the case of the riskier riding intentions [R2 ranging from 57% - 66%] than the safer riding intentions [R2 ranging from 22% - 36%]. Therefore, this type of theoretical model may be better suited to investigating deliberate risk-taking intentions rather than an overall model of rider behaviour which includes errors and lapses or intentions to ride safely.----- In the final analyses, perceived behavioural control (PBC) proved to be a significant predictor of all four intentions towards the safer behaviours, and also towards intentions to "push my limits". Attitude was a significant predictor of the three riskier intentions. Although the standard subjective norm variable performed weakly, as it was only predictive of one intention, the specific subjective norm (i.e., the people that someone rides with) emerged as a significant predictor of four of the seven intention items and group norm was predictive of an additional intention item. This result indicates that the other people a person rides with may have a marked effect on behavioural intentions. Sensation seeking was found to be significantly related to four intentions, self identification as a safe or risky rider related to two intentions and a propensity for aggression was only significantly predictive of one intention.----- Study 2 did not find a significant relationship between the seven intentions and past crash history. However, correlational analyses found that people who had reported being involved in a serious crash in the past two years reported less PBC over their ability to ride as safely as possible and to perform stunts and/or ride at extreme speeds.----- In conclusion, this program of research provided insight into the issues riders feel are important to their safety, and has facilitated a greater understanding of the complexity of influences that impact on riding intentions and behaviour. The study also provided support for extending the traditional TPB model to include other measures of social influence, as well as person-related factors such as sensation seeking. The fact that PBC emerged as a predictor of five of the seven intentions suggests that there may be scope to enhance existing training practices to better address both safe and risky riding intentions. The influence of other riders also emerged as a strong influence on intentions, suggesting that strategies to address rider behaviour within the wider social context of riding may be a useful addition to future motorcycle safety or rider training initiatives. The social dynamics of motorcycle riding, within the context of road safety, is an area that clearly requires more investigation. Research into this area may provide the key to developing new approaches to promoting motorcycle safety which effectively integrate both the psychological and sociological aspects of riding; therefore, better reflecting the real challenges facing many riders on Australian roads today.

A tese apresenta um panorama global e atual da inserção da motocicleta em países representativos dos sete continentes, com ênfase no Brasil. Para isso, foram feitas análises sobre quatro elementos da realidade da motocicleta no mundo: (i) a propriedade, analisada através dos dados das frotas mundiais; (ii) os diferentes usos das motocicletas; (iii) os acidentes com motociclistas, através de uma reflexão sobre dados de acidentalidade, suas consequências para a sociedade e possíveis intervenções; (iv) as práticas de operação das motocicletas empregadas em algumas cidades do mundo. Após, foi proposto o desenvolvimento de procedimentos padronizados para a coleta de dados na identificação do corredor virtual e a criação de um método para análise desses corredores, quanto as suas diversas características. O método proposto incorpora análises quantitativas e qualitativas da operação da motocicleta em corredor virtual. Foram escolhidos como parâmetros para a criação do método alguns elementos físicos para caracterizar o corredor virtual, como velocidades praticadas pelas motocicletas ao estarem operando no corredor, acelerações, desacelerações e larguras do corredor virtual. Foi realizada, também, uma análise observacional do comportamento de cada motocicleta pesquisada, com ênfase nas particularidades dos movimentos. A aplicação do método envolveu a análise de dados coletados na cidade de Porto Alegre, Rio Grande do Sul. Na aplicação do método, os resultados mostram que a velocidade média adquirida pela motocicleta não depende somente da variável largura do corredor virtual. Também identificam as larguras mínimas e máximas usadas pelos motociclistas nos corredores virtuais, nos ambientes estudados. O estudo de caso mostrou que a aplicação do método proposto é simples, sendo possível a sua transferência a outras realidades brasileiras. / This thesis presents a global and current overview of the insertion of motorcycle in representative countries of the seven continents, with an emphasis on Brazil. For that, four elements about reality’s motorcycle in the world were analyzed: (i) ownership, analyzed through the data of world fleet; (ii) the different uses of motorcycles; (iii) accidents involving motorcyclists, its consequences for society and interventions possible; (iv) operation practices currently in place in some cities of the world. Beyond that, it was development standardized procedures to collection data that identified the lane sharing and was created a method to analyzing these lanes, about its some characteristics. The method analyzed quantitative and qualitative data around the motorcycle’s operation on a lane sharing, and the parameters used were some physical elements to characterize the lane sharing, as speeds practiced by the motorcycles in operation in the corridor, accelerations, decelerations and widths of the lane sharing. Was also performed an observational analysis on the behavior of each motorcycle researched, with emphasis in a particularities of the movements. The model was applied based on data collect in the city of Porto Alegre, Rio Grande do Sul. The results showed that the average speed acquired by motorcycle not depends only on the width of the lane sharing. Also identified the minimum and maximum widths used by motorcyclists in lane sharing in the study’s place. The case showed that the application of the proposed method is simple, and may be transferred to other Brazilian’s realities.

A tese apresenta um panorama global e atual da inserção da motocicleta em países representativos dos sete continentes, com ênfase no Brasil. Para isso, foram feitas análises sobre quatro elementos da realidade da motocicleta no mundo: (i) a propriedade, analisada através dos dados das frotas mundiais; (ii) os diferentes usos das motocicletas; (iii) os acidentes com motociclistas, através de uma reflexão sobre dados de acidentalidade, suas consequências para a sociedade e possíveis intervenções; (iv) as práticas de operação das motocicletas empregadas em algumas cidades do mundo. Após, foi proposto o desenvolvimento de procedimentos padronizados para a coleta de dados na identificação do corredor virtual e a criação de um método para análise desses corredores, quanto as suas diversas características. O método proposto incorpora análises quantitativas e qualitativas da operação da motocicleta em corredor virtual. Foram escolhidos como parâmetros para a criação do método alguns elementos físicos para caracterizar o corredor virtual, como velocidades praticadas pelas motocicletas ao estarem operando no corredor, acelerações, desacelerações e larguras do corredor virtual. Foi realizada, também, uma análise observacional do comportamento de cada motocicleta pesquisada, com ênfase nas particularidades dos movimentos. A aplicação do método envolveu a análise de dados coletados na cidade de Porto Alegre, Rio Grande do Sul. Na aplicação do método, os resultados mostram que a velocidade média adquirida pela motocicleta não depende somente da variável largura do corredor virtual. Também identificam as larguras mínimas e máximas usadas pelos motociclistas nos corredores virtuais, nos ambientes estudados. O estudo de caso mostrou que a aplicação do método proposto é simples, sendo possível a sua transferência a outras realidades brasileiras. / This thesis presents a global and current overview of the insertion of motorcycle in representative countries of the seven continents, with an emphasis on Brazil. For that, four elements about reality’s motorcycle in the world were analyzed: (i) ownership, analyzed through the data of world fleet; (ii) the different uses of motorcycles; (iii) accidents involving motorcyclists, its consequences for society and interventions possible; (iv) operation practices currently in place in some cities of the world. Beyond that, it was development standardized procedures to collection data that identified the lane sharing and was created a method to analyzing these lanes, about its some characteristics. The method analyzed quantitative and qualitative data around the motorcycle’s operation on a lane sharing, and the parameters used were some physical elements to characterize the lane sharing, as speeds practiced by the motorcycles in operation in the corridor, accelerations, decelerations and widths of the lane sharing. Was also performed an observational analysis on the behavior of each motorcycle researched, with emphasis in a particularities of the movements. The model was applied based on data collect in the city of Porto Alegre, Rio Grande do Sul. The results showed that the average speed acquired by motorcycle not depends only on the width of the lane sharing. Also identified the minimum and maximum widths used by motorcyclists in lane sharing in the study’s place. The case showed that the application of the proposed method is simple, and may be transferred to other Brazilian’s realities.

A tese apresenta um panorama global e atual da inserção da motocicleta em países representativos dos sete continentes, com ênfase no Brasil. Para isso, foram feitas análises sobre quatro elementos da realidade da motocicleta no mundo: (i) a propriedade, analisada através dos dados das frotas mundiais; (ii) os diferentes usos das motocicletas; (iii) os acidentes com motociclistas, através de uma reflexão sobre dados de acidentalidade, suas consequências para a sociedade e possíveis intervenções; (iv) as práticas de operação das motocicletas empregadas em algumas cidades do mundo. Após, foi proposto o desenvolvimento de procedimentos padronizados para a coleta de dados na identificação do corredor virtual e a criação de um método para análise desses corredores, quanto as suas diversas características. O método proposto incorpora análises quantitativas e qualitativas da operação da motocicleta em corredor virtual. Foram escolhidos como parâmetros para a criação do método alguns elementos físicos para caracterizar o corredor virtual, como velocidades praticadas pelas motocicletas ao estarem operando no corredor, acelerações, desacelerações e larguras do corredor virtual. Foi realizada, também, uma análise observacional do comportamento de cada motocicleta pesquisada, com ênfase nas particularidades dos movimentos. A aplicação do método envolveu a análise de dados coletados na cidade de Porto Alegre, Rio Grande do Sul. Na aplicação do método, os resultados mostram que a velocidade média adquirida pela motocicleta não depende somente da variável largura do corredor virtual. Também identificam as larguras mínimas e máximas usadas pelos motociclistas nos corredores virtuais, nos ambientes estudados. O estudo de caso mostrou que a aplicação do método proposto é simples, sendo possível a sua transferência a outras realidades brasileiras. / This thesis presents a global and current overview of the insertion of motorcycle in representative countries of the seven continents, with an emphasis on Brazil. For that, four elements about reality’s motorcycle in the world were analyzed: (i) ownership, analyzed through the data of world fleet; (ii) the different uses of motorcycles; (iii) accidents involving motorcyclists, its consequences for society and interventions possible; (iv) operation practices currently in place in some cities of the world. Beyond that, it was development standardized procedures to collection data that identified the lane sharing and was created a method to analyzing these lanes, about its some characteristics. The method analyzed quantitative and qualitative data around the motorcycle’s operation on a lane sharing, and the parameters used were some physical elements to characterize the lane sharing, as speeds practiced by the motorcycles in operation in the corridor, accelerations, decelerations and widths of the lane sharing. Was also performed an observational analysis on the behavior of each motorcycle researched, with emphasis in a particularities of the movements. The model was applied based on data collect in the city of Porto Alegre, Rio Grande do Sul. The results showed that the average speed acquired by motorcycle not depends only on the width of the lane sharing. Also identified the minimum and maximum widths used by motorcyclists in lane sharing in the study’s place. The case showed that the application of the proposed method is simple, and may be transferred to other Brazilian’s realities.

Doctor of Philosophy / Department of Civil Engineering / Sunanda Dissanayake / Lane-departure crashes are the most predominant crash type in Kansas which causes very high number of motor vehicle fatalities. Therefore, the Kansas Department of Transportation (KDOT) has implemented several different types of countermeasures to reduce the number of motor vehicle fatalities associated with lane-departure crashes. This research was conducted to estimate the safety effectiveness of commonly used lane-departure countermeasures in Kansas on all crashes and lane-departure crashes using Crash Modification Factors (CMFs). Paved shoulders, rumble strips, safety edge treatments and median cable barriers were identified as the commonly used lane-departure countermeasures on both tangent and curved road segments while chevrons and post-mounted delineators were identified as the most commonly used lane-departure countermeasures on curved road segments. This research proposes a state-of-art method of estimating CMFs using cross-sectional data for chevrons and post-mounted delineators. Furthermore, another state-of-art method is proposed in this research to estimate CMFs for safety edge treatments using before-and-after data. Considering the difficulties of finding the exact date of implementation of each countermeasure, both cross-sectional and before-and-after studies were employed to estimate the CMFs. Cross-sectional and case-control methods, which are the two major methods in cross-sectional studies were employed to estimate CMFs for paved shoulders, rumble strips, and median cable barriers. The conventional cross-sectional and case-control methods were modified when estimating CMFs for chevrons and post-mounted delineators by incorporating environmental and human behaviors in addition to geometric and traffic-related explanatory variables. The proposed method is novel and has not been used in the previous cross-sectional models available in the literature. Generalized linear regression models assuming negative binomial error structure were used to develop models for cross-sectional method to estimate CMFs while logistic regression models were used to estimate CMFs using case-control method. Results showed that incorporating environmental and human-related variables into cross-sectional models provide better model fit than in conventional cross-sectional models. To validate the developed models for cross-sectional method, mean of the residuals and the Root Mean Square Error (RMSE) were used. For the case-control method, Receiver Operational Characteristic (ROC) was used to evaluate the predictive power of models for a binary outcome using classification tables. However, it was seen that the case-control method is not suitable for estimating CMFs for all crashes since the range of the crash frequency is wide in each road segment. A regression-based method of estimating CMFs using before-and-after data was proposed to estimate CMFs for safety edge treatments. This method allows researchers to identify the safety effectiveness of an individual CMFs on road segments where multiple treatments have been applied at the same time. Since this method uses road geometric and traffic-related characteristics in addition to countermeasure information as the explanatory variables, the model itself would be the Safety Performance Function (SPF). Therefore, developing new SPF is not necessary. Finally, the CMFs were estimated using before-and-after Empirical Bayes method to validate the results from the regression-based method. The results of this study can be used as a decision-making tool when implementing lane-departure countermeasures on similar roadways in Kansas. Even though there are readily available CMFs from the national level studies, having more localized CMFs will be beneficial due to differences in traffic-related and geometric characteristics on different roadways.

Since before the release of the Highway Safety Manual research has been indicating the need to incorporate mobility and control aspects to road safety analysis. The first part of this work developed and implement in an existing computational engine a signal timing optimization method that considers mobility, safety, and emissions measures simultaneously. A sensitivity analysis was conducted to provide insight on the practical effects and order of relevance of 20 key input variables. Mobility improvement performance usually coincides with emissions improvements, but sometimes at the expense of safety. The second part of this work investigated the relationship between hourly traffic density and crash rates on Brazilian expressways with different characteristics, based on a database containing over 20,000 crashes and more than 35 million traffic volume observations and. The resulting curves for urban expressways follow a U shape, with minimum values associated with LOS B to C, while the relationships for rural expressways were found to be continuously increasing, suggesting that low volume rural roads are safer than the higher volume ones. The analysis of other influencing factors revealed that nighttime conditions, weaving segments and urban multilane highways could be related to higher crash rates. The third part of the project extends the analysis to crash severity modeling, using an ordered response choice model. The framework that better fit this database led to the development of two different models: single-vehicle crashes (SV) and multiple-vehicle crashes (MV), since the factors that explain the severity of crashes varies widely between these models. For instance, guardrails and barriers proved to effectively reduce severity for SV crashes, for which run-offs are the most severe crash type. The unique database used in this study also allowed for an investigation of the influence of prevailing traffic conditions on crash severity, while still controlling for all other factors. The results suggested that multiple-vehicle crash severity is negatively related with traffic density, while single-vehicle crashes are more closely related to speed. The findings of this work have implications to policy and design decisions, and the produced equation could be incorporated to active traffic management (ATM) and HCM reliability analysis. / Desde antes da publicação do Highway Safety Manual, vários pesquisadores indicam a necessidade de se incorporar aspectos de operação de tráfego à análise de segurança viária. A primeira parte deste trabalho desenvolveu e implementou em uma ferramenta computacional existente um método de otimização de tempos semafóricos que considera medidas de desempenho de operação, segurança e emissões simultaneamente. Uma análise de sensibilidade foi realizada para produzir conhecimento sobre os efeitos práticos e a ordem de relevância de 20 variáveis de entrada principais. O desempenho da programação semafórica em termos de redução dos atrasos geralmente coincide com redução das emissões, embora às vezes às custas da segurança. A segunda parte deste trabalho investigou a relação entre a densidade horária de tráfego e as taxas de acidentes em autoestradas e rodovias de pista dupla brasileiras com características diversas, com base em um banco de dados contendo mais de 20.000 registros de acidentes e mais de 35 milhões de observações de tráfego. As curvas resultantes para rodovias urbanas seguem um formato em U, com valores mínimos associados aos níveis de serviço B a C, enquanto que as relações para as rodovias rurais são contínuas e crescentes, sugerindo que rodovias rurais de baixo volume são mais seguras do que as de maior volume. A análise de outros fatores revelou que condições noturnas, segmentos de entrelaçamento e rodovias de pista dupla convencionais urbanas estariam relacionadas a maiores taxas de acidentes. A terceira parte deste projeto amplia a análise para modelagem de severidade dos acidentes, usando um modelo de escolha discreta ordenado. A estrutura que melhor se adequa a esse banco de dados levou ao desenvolvimento de dois modelos diferentes: acidentes com um veículo e acidentes com múltiplos veículos, já que os fatores que explicam a severidade dos acidentes variam muito entre esses modelos. Por exemplo, defensas e barreiras se mostraram efetivas para a redução da severidade de acidentes com um veículo, para as quais a saída de pista é o tipo de acidente mais grave. O amplo banco de dados usado neste estudo também permitiu uma investigação da influência das condições de tráfego na severidade do acidente, em comparação com todos os outros fatores. Os resultados sugeriram que a severidade de acidentes de múltiplos veículos está negativamente relacionada com a densidade de tráfego, enquanto colisões com um único veículo estão mais relacionadas à velocidade. As descobertas deste trabalho têm implicações nas decisões sobre políticas e projetos de transportes, e a equação produzida pode ser incorporada à análise de confiabilidade do gerenciamento ativo do tráfego (ATM) e do Highway Capacity Manual.

In the United States, motor vehicle crashes are one of the leading causes of unintentional injury death and disability for children ages 1'15 years. Despite local, state, and federal legislative and educational efforts, children continue to be restrained improperly and thus face harm. Identifying behaviors and barriers that place child occupants at risk is crucial for implementing focused, injury-prevention programs and policies. The purpose of this study was to evaluate the effectiveness of Connecticut's child passenger safety law that was strengthened in 2005. This study involved a multifactorial approach to predicting child seat use, guided by Roger's diffusion of innovations as the theoretical framework. The analysis determined if there was a difference in the prevalence of car seat use before as compared to after law implementation and identified variables that best predicted the use of car seats and premature transition to a seat belt. Using Connecticut's Crash Data Repository, a logistic regression analysis indicated that car seat use was 1.3 times more likely post law (OR 0.75; 95% CI: 0.65-0.86) and that in particular, children ages 4, 5, and 6 (combined) were most positively affected by the law (OR 0.67; 95% CI 0.54-0.82). Driver sex, crash time of day, child age, and child seating position were all determined to be significant predictors of whether or not a child was in a child safety seat. Additionally, these variables were also determined to be predictors of early transition to use of a lap/shoulder belt (versus child seat). The social change implication of this study is that identifying predictors of car seat use and early transition helps to formulate and implement injury prevention measures that could in turn help to decrease medical costs, save lives, and prevent injuries.

Current literature predicts that climate change may increase both the occurrence and severity of heavy rainfall events and winter precipitation in the Northeast United States. A potential increase in intense precipitation events related to climate change would theoretically also cause an increase in weather-related delays, increase in overall traffic disruptions, a substantive shift in travel behavior, and presumably a negative effect on safety and maintenance operations of highways. This current research study examines the existing impacts from both an operational and behavioral perspective of how weather events currently impact overall safety along routes in Massachusetts. A secondary objective of the research effort is to evaluate the extent to which this information is captured on the crash report form for subsequent use in safety analyses. Utilizing data from Massachusetts Department of Transportation, National Climatic Data Center (NCDC) and the University of Massachusetts Data Warehouse, crash statistics were examined during varied levels of weather events and compared with non-weather conditions. In addition, crash report forms were analyzed in comparison to NCDC weather data to determine the correlation between of the weather specific fields of the reports and to help determine if crashes were weather-related. The results from the investigation show how the character of precipitation events impact traffic safety including both occurrence and intensity levels and in conjunction with existing weather predictions the relationships developed in this study are useful in evaluating how changes in extreme precipitation events projected for the Northeast may impact drivers’ safety in the future.

No description available.