The onset of a yellow indication is typically associated with the risk of vehicle crashes resulting from dilemma-zone and red-light-running problems. Such risk of vehicle crashes is greater for high-speed signalized intersection approaches. The research presented in this dissertation develops statistical as well as behavioral frameworks for modeling driver behavior while approaching high-speed signalized intersection approaches at the onset of a yellow indication. The analysis in this dissertation utilizes two sources of data. The main source is a new dataset that was collected as part of this research effort during the summer of 2008. This experiment includes two instructed speeds; 72.4 km/h (45 mph) with 1727 approaching trials (687 running and 1040 stopping), and 88.5 km/h (55 mph) with 1727 approaching trials (625 running and 1102 stopping). The complementary source is an existing dataset that was collected earlier in the spring of 2005 on the Virginia Smart Road facility. This dataset includes a total of 1186 yellow approaching trials (441 running and 745 stopping). The adopted analysis approach comprises four major parts that fulfill the objectives of this dissertation. The first part is concerned with the characterization of different driver behavioral attributes, including driver yellow/red light running behavior, driver stop-run decisions, driver perception-reaction times (PRT), and driver deceleration levels. The characterization of these attributes involves analysis of variance (ANOVA) and frequency distribution analyses, as well as the calibration of statistical models. The second part of the dissertation introduces a novel approach for computing the clearance interval duration that explicitly accounts for the reliability of the design (probability that drivers do not encounter a dilemma zone). Lookup tables are developed to assist practitioners in the design of yellow timings that reflects the stochastic nature of driver PRT and deceleration levels. An extension of the proposed approach is presented that can be integrated with the IntelliDriveSM initiative. Furthermore, the third part of the dissertation develops an agent-based Bayesian statistics approach to capture the stochastic nature of the driver stop-run decision. The Bayesian model parameters are calibrated using the Markov Chain Monte Carlo (MCMC) slice procedure implemented within the MATLAB® software. In addition, two procedures for the Bayesian model application are illustrated; namely Cascaded regression and Cholesky decomposition. Both procedures are demonstrated to produce replications that are consistent with the Bayesian model realizations, and capture the parameter correlations without the need to store the set of parameter realizations. The proposed Bayesian approach is ideal for modeling multi-agent systems in which each agent has its own unique set of parameters. Finally, the fourth part of the dissertation introduces and validates a state-of-the-art behavioral modeling framework that can be used as a tool to simulate driver behavior after the onset of a yellow indication until he/she reaches the intersection stop line. The behavioral model is able to track dilemma zone drivers and update the information available to them every time step until they reach a final decision. It is anticipated that this behavioral model will be implemented in microscopic traffic simulation software to enhance the modeling of driver behavior as they approach signalized intersections. / Ph. D.

Esta pesquisa caracterizou o comportamento de motoristas em interseções semaforizadas sob três aspectos: (1) reação frente à mudança do verde para o amarelo; (2) comportamento durante a desaceleração para parar; e (3) comportamento durante a saída do cruzamento semaforizado. Os dados foram coletados em uma interseção localizada em pista de testes no Virginia Tech Transportation Institute, nos EUA. A amostra foi composta por 60 motoristas voluntários igualmente divididos em função do gênero; dos quais 32 tinham idade inferior a 65 anos (\"jovens\"). Foram investigados efeitos da idade, do gênero e da declividade da via sobre as seguintes situações: tomada de decisão entre parar ou prosseguir no amarelo; posição de parada em relação à faixa de retenção; tempo de percepção e reação (TPR) para frenagem e partida do cruzamento; efeito de zonas de opção e de dilema; taxa de desaceleração para parada na interseção; e taxa de aceleração para partida da interseção. As análises indicaram que: (1) os motoristas mais jovens invadiram mais a faixa de retenção que os idosos; (2) mulheres apresentam maiores TPR para decidir partir da interseção; e (3) o TPR é menor no declive tanto para a decisão de frear quanto para a partida do cruzamento. As taxas de desaceleração não apresentaram influência dos fatores avaliados. Por outro lado, constatou-se que a aceleração foi afetada pelo fator declividade. Como resultado final da pesquisa, foram propostos modelos, em função do tempo, que exprimem a desaceleração/aceleração usada pelos motoristas ao frear/acelerar. Foram propostos modelos para o motorista médio e para motoristas desagregados em três grupos em função da agressividade. / The objective of this research was to characterize driver behavior at signalized intersections according to three aspects: (1) reaction at the onset of the amber phase; (2) behavior during the deceleration to stop at the signal; and (3) behavior during the acceleration to leave the intersection at the onset of the green. The data were collected at a signalized intersection on a private highway, at the Virginia Tech Transportation Institute, in the USA. The sample consisted of 60 volunteer drivers, equally divided by gender. The sample was divided into two age groups: younger drivers (age was less than 65) and older drivers. Effects of gender, age group and roadway grade were investigated for the following aspects: decision making at the onset of amber; final stopping position with relation to the stop line; perception/reaction times (PRT) at the onset of the amber and the green lights; effects of dilemma and option zones; and deceleration and acceleration rates used by the drivers. The analyses suggest that: (1) younger drivers tend to stop farther past the stop line, compared to older drivers; (2) women have longer PRT at the onset of the green; and (3) PRT are shorter on downgrade at the onset of both amber and green lights. The observed deceleration rates were not affected by gender, age group or roadway grade. Acceleration rates were found to be influenced by the grade. A set of models that express the acceleration/deceleration rates as a function of time were proposed to represent the average behavior observed for drivers in the sample. Specific models were also proposed for aggressive, non-aggressive and intermediate drivers.

Esta pesquisa caracterizou o comportamento de motoristas em interseções semaforizadas sob três aspectos: (1) reação frente à mudança do verde para o amarelo; (2) comportamento durante a desaceleração para parar; e (3) comportamento durante a saída do cruzamento semaforizado. Os dados foram coletados em uma interseção localizada em pista de testes no Virginia Tech Transportation Institute, nos EUA. A amostra foi composta por 60 motoristas voluntários igualmente divididos em função do gênero; dos quais 32 tinham idade inferior a 65 anos (\"jovens\"). Foram investigados efeitos da idade, do gênero e da declividade da via sobre as seguintes situações: tomada de decisão entre parar ou prosseguir no amarelo; posição de parada em relação à faixa de retenção; tempo de percepção e reação (TPR) para frenagem e partida do cruzamento; efeito de zonas de opção e de dilema; taxa de desaceleração para parada na interseção; e taxa de aceleração para partida da interseção. As análises indicaram que: (1) os motoristas mais jovens invadiram mais a faixa de retenção que os idosos; (2) mulheres apresentam maiores TPR para decidir partir da interseção; e (3) o TPR é menor no declive tanto para a decisão de frear quanto para a partida do cruzamento. As taxas de desaceleração não apresentaram influência dos fatores avaliados. Por outro lado, constatou-se que a aceleração foi afetada pelo fator declividade. Como resultado final da pesquisa, foram propostos modelos, em função do tempo, que exprimem a desaceleração/aceleração usada pelos motoristas ao frear/acelerar. Foram propostos modelos para o motorista médio e para motoristas desagregados em três grupos em função da agressividade. / The objective of this research was to characterize driver behavior at signalized intersections according to three aspects: (1) reaction at the onset of the amber phase; (2) behavior during the deceleration to stop at the signal; and (3) behavior during the acceleration to leave the intersection at the onset of the green. The data were collected at a signalized intersection on a private highway, at the Virginia Tech Transportation Institute, in the USA. The sample consisted of 60 volunteer drivers, equally divided by gender. The sample was divided into two age groups: younger drivers (age was less than 65) and older drivers. Effects of gender, age group and roadway grade were investigated for the following aspects: decision making at the onset of amber; final stopping position with relation to the stop line; perception/reaction times (PRT) at the onset of the amber and the green lights; effects of dilemma and option zones; and deceleration and acceleration rates used by the drivers. The analyses suggest that: (1) younger drivers tend to stop farther past the stop line, compared to older drivers; (2) women have longer PRT at the onset of the green; and (3) PRT are shorter on downgrade at the onset of both amber and green lights. The observed deceleration rates were not affected by gender, age group or roadway grade. Acceleration rates were found to be influenced by the grade. A set of models that express the acceleration/deceleration rates as a function of time were proposed to represent the average behavior observed for drivers in the sample. Specific models were also proposed for aggressive, non-aggressive and intermediate drivers.

<p>Profesionalnim vozačima osnovno zanimanje je upravljanje motornim vozilom. Izvođenje radnih zadatka podrazumeva stalnu napregnutost pažnje vezanu za vidne i zvučne podražaje koji se brzo smenjuju, &scaron;to zahteva da vozač adekvatno i tačno reaguje na promene. Prijem informacija, obrada, dono&scaron;enje odluke i izvr&scaron;avanje motornog odgovora su procesi koji prate jedni druge i čine vreme percepcije-reakcije (VPR). Uslovi i zahtevi rada za profesionalne vozače su isti i za mlađe i starije radnike i povezani su sa velikom odgovorno&scaron;ću za ljudske živote i materijalna dobra, bez obzira na to &scaron;to je poznato, da se radna sposobnost menja zbog prirodnog procesa starenja. Merenje i utvrđivanje vrednosti VPR je važan deo ispitivanja u okviru procene zdravstvene sposobnosti za bezbednu vožnju. Ciljevi: Utvrđivanje vrednosti VPR kod profesionalnih vozača i poređenje sa kontrolnom grupom. Ispitivanje uticaja starosti i vozačkog iskustva na VPR kod profesionalnih vozača. Materijal i metode : Ova studija procenjuje deo sposobnosti profesionalnih vozača merenjem VPR prostog i složenog, važnih za sigurnost u vožnji. Istraživanje je sprovedeno u vremenskom periodu od devet meseci i obuhvatilo je 548 ispitanika mu&scaron;kog pola, starosti od 21 do 65 godina. Eksperimentalnu grupu je činilo 278 ispitanika (profesionalni vozači), a kontrolnu 270 ispitanika kojima osnovno zanimanje nije profesionalna vožnja. Testiranje je izvedeno pomoću hardversko-softverskog sistema za određivanje vrednosti VPR na proste i složene audio-vizuelne podražaje. Merenja su sprovedena na tri nivoa težine zadatka: prosto VPR, i testovi složenog VPR na promenu pozicije podražaja i vrste boje. Rezultati: Utvrđene su značajno niže srednje vrednosti VPR na sva tri nivoa testiranja u grupi profesionalnih vozača u poređenju sa kontrolnom grupom. Utvrđena je pozitivna povezanost srednjih vrednosti VPR sa godinama života i dužinom profesionalnog vozačkog radnog staža na svim testovima u grupi profesionalnih vozača. Nisu utvrđene značajne razlike u procentu pogre&scaron;nih odgovora u odnosu na životno doba i dužinu vozačkog staža, &scaron;to govori o pozitivnim efektima profesionalne prakse u vožnji. Nisu utvrđene značajne razlike srednjih vrednosti VPR kod vozača u gradskom ili međugradskom saobraćaju, kao i u odnosu na broj pređenih kilometara mesečno na svim testovima. Obeležja poput starosti (godine života), profesionalne prakse (iskustvo u godinama profesionalne vožnje), neke promene zdravstvenog stanja (postojanje bolesti ili drugih poremećaja) u grupi profesionalnih vozača pokazale su se kao prediktori sa značajnim nivoom povezanosti sa vrednostima VPR. Metodom vi&scaron;estruke regresione analize smo ispitali smo povezanost vrednosti VPR sa posmatranim prediktorima kada ih analiziramo zajedno uzimajući u obzir njihovu međusobnu interakciju. Regresioni model pokazuje kako skup posmatranih obeležja predviđa promene VPR. Zaključak: Utvrđene vrednosti i prediktivni model promena VPR profesionalnih vozača mogu biti korisni podaci u svakodnevnom radu zdravstvenim ustanovama koje procenjuju vozačku sposobnost, kako bi se identifikovali potencijalno rizični vozači sa vi&scaron;im vrednostima VPR, zamorenih i osoba sa početnim o&scaron;tećenjima nervnog sistema, sklonih povredama u saobraćaju i na radu, u cilju prevencije saobraćajnih udesa i povreda, kao i osiguranja da vozači imaju sposobnosti neophodne za bezbednu vožnju. Utvrđene vrednosti VPR mogle bi naći primenu pri oceni radne sposobnosti i kod radnika na drugim zanimanjima gde se očekuje brza i tačna reakcija na određeni podražaj.</p> / <p>The term professional driver refers to people whose main occupation is driving a motor vehicle. Performing work tasks implies a constant strain of attention related to visual and audible stimuli that change quickly, which requires the driver to respond adequately and accurately to changes. Receiving information, processing, making a decision and executing a motor response are processes that accompany each other and make up the perception-reaction time (PRT). The working conditions and requirements for professional drivers are the same for both younger and older workers and are associated with great responsibility for human lives and material goods, regardless of the fact that it is known that working ability changes due to the natural aging process. Measuring and determining the value of PRT is an important part of testing as part of the assessment of health fitness for safe driving. Aims: Determination of PRT values in professional drivers and comparison with the control group. Examination of the effects of aging and driving experience on the PRT of professional drivers. Material and methods: This study assesses part of the ability of professional drivers by measuring simple and complex PRT important for driving safety. The study was conducted over a period of nine months and included 548 male respondents, aged 21 to 65 years. The experimental group consisted of 278 respondents (professional drivers), and the control group consisted of 270 respondents whose main occupation is not professional driving. Testing was performed using a hardware-software system to determine the value of PRT on simple and complex audio-visual stimuli. Measurements were carride out at three levels of task difficulty: simple PRT, and complex PRT tests to change stimuli position and color type. Results: Significantly lower PRT mean values were found at all three levels of testing in the group of professional drivers compared to the control group. A positive correlation was found between the mean PRT values with age and experience of professional driving on all tests in the group of professional drivers. No significant differences were found in the percentage of incorrect answers in relation to the age and driving experience, which shows the positive effects of professional driving practice. No significant differences were found in the mean PRT values on all tests for drivers in urban or interurban traffic and in relation to the number of kilometers per month. Individual characteristics as, aging, professional practice (experience in years of professional driving), changes in health status (existence of diseases or other disorders) in the group of professional drivers showed to be predictors with a significant level of correlation with PRT values. Using the method of multiple regression analysis, we examined the correlation of PRT values with the observed predictors when we analyze them together, taking into account their mutual interaction.The regression model shows how the set of observed features predicts changes in PRT. Conclusion: The determined values and the predictive model of changes PRT of professional drivers can be useful data in the daily work of health institutions that assess driving ability, in order to identify potentially risky drivers with higher PRT values,, tired and people with initial nervous system damage, prone to traffic injuries and at work, in order to prevent traffic accidents and injuries, as well as to ensure that drivers have the skills necessary for safe driving. The determined values of PRT could be used in the assessment of work ability and in workers in other occupations where a quick and accurate response to a particular stimulus is expected.</p>