In 2018 the Utah Department of Transportation (UDOT) funded a study in which data were collected to evaluate performance measures for UDOT's Incident Management Team (IMT) program. After that study was completed, UDOT received funding to expand the size of its IMT program. Additionally, TransSuite, a data source used by the UDOT Traffic Operations Center to log incident-related data, was reconfigured to provide a higher quantity of performance measure data. This study made use of the new data source, in addition to Computer Aided Dispatch logs provided by the Utah Highway Patrol that were used in the first study, to collect performance measure data of the expanded program and measure the impacts of the IMT program expansion. Using these two datasets, a reanalyzed 2018 dataset and a new 2020 dataset, a comparison of performance measures was made. Performance measures studied included those defined as important by the Federal Highway Administration's Focus States Initiative in 2009, namely Roadway Clearance Time, Incident Clearance Time, and Response Time. These performance measures were calculated for IMT responders at 320 incidents in 2018 and 289 incidents in 2020. In addition, data regarding the affected volume associated with incidents, the excess travel time accumulated due to incidents, and the excess user cost associated with incident congestion were gathered. In 2018, 188 incidents were analyzed for these user impacts, and in 2020 144 incidents were analyzed. Statistical analyses were conducted to compare IMT performance between the two years and to determine relationships between performance measures and user impacts. The effects of the COVID-19 pandemic affected traffic volumes during this study, and statistical analyses were adjusted to account for volume differences between the two years. Results indicated that the expansion of the IMT program has allowed UDOT to respond faster to incidents, and respond to a larger quantity of incidents over a larger coverage area and in extended operating hours. Performance of the expanded IMT program has had significant effects in reducing incident-related congestion and its costs.

In 2009 the Federal Highway Administration published a report regarding a Focus States Initiative that had been conducted with 11 states to discuss the development of national Traffic Incident Management (TIM) standards. Performance measures were defined, and a national TIM dashboard created, but very little data has been added to the dashboard since. In this research study, performance measures of the Utah Department of Transportation (UDOT) TIM program were analyzed. Data availability was first assessed to determine whether these performance measures could be calculated. It was determined that crash response data available from the Utah Highway Patrol (UHP) could be used to calculate the performance measures of Incident Management Teams (IMT) and UHP units; however, roadway clearance data were missing. UHP personnel agreed to collect additional data regarding crash roadway clearance for six months of the study. Performance measures of response time (RT), roadway clearance time (RCT), and incident clearance time (ICT) were calculated for responding units at 168 crashes. Using the crash response data from UHP and traffic speed, travel time, and volume data from UDOT databases, 83 of the 163 crashes that met additional criteria were evaluated to determine the volume of traffic affected (AV) by each incident and the associated user cost (EUC). Statistical analyses to determine relationships between different measures such as RT, RCT, ICT, AV, and EUC were conducted to assist UDOT in optimizing the allocation of their IMT resources.

In 2019, the Utah Department of Transportation (UDOT) funded a research study evaluating the performance measures of UDOT's expanded Incident Management Team (IMT) program. The number of IMTs patrolling Utah roadways increased from 13 to 25 between 2018 and 2020. Crash data were collected from the Utah Highway Patrol's Computer Aided Dispatch database and from the UDOT TransSuite database to compare IMT performance measures between the two years and to evaluate the benefits of the expanded IMT program. However, these data were compromised due to the effects of the COVID-19 pandemic. This study collected data for 2022 using the same methodology as the Phase II study to compare IMT performance measures in 2022 with those of 2018 after traffic volumes had returned to a similar level as those of pre-pandemic levels. There were 283 and 307 incidents for the years of 2018 and 2022, respectively, that were analyzed for IMT performance measures which include response time, roadway clearance time, and incident clearance time. There were 172 and 236 incidents for the years of 2018 and 2022, respectively, that were analyzed for user impacts which were affected volume, excess travel time, and excess user costs. Results of the statistical analyses conducted on the 2018 and 2022 datasets show that IMTs can respond more quickly to incidents in a larger coverage area with significantly reduced user impacts. The expanded IMT program is also able to respond to more incidents, including those of high severity, while significantly decreasing congestion.

Although public transit bus accounts for only a small percentage of the mode share for transportation in Florida, the annual passenger miles were over 1 billion with over 200 million passenger trips in 2005. These numbers warrant close attention to be paid to the safety of public transit vehicles. Despite the relatively low occurrence of fatalities and bus crashes, each crash of a high occupancy vehicle such as a public transit bus could expose more people to injury than a private automobile crash. Bus crashes also have a significant impact on the automobiles that are involved. Since a high percentage of bus crashes in Florida are caused by rear-end collisions with private automobiles, improving the signage and lighting that will allow buses to move back into traffic safely is very important for bus safety and operations. This paper uses bus operator surveys, crash data, and field studies to develop recommendations for lighting and signage on the back of the bus, roadway signs and revised Florida legislations. Improved signage and lighting will help the bus move back into traffic safely, decrease bus delay and improve bus operations however it must be accompanied by laws and law enforcement.

Because the operational characteristics of signalized intersections near highway-railroad grade crossings (IHRGCs) are different from those of signalized intersections located elsewhere in the traffic system, standard operational strategies do not apply. This is because safe operation at IHRGCs takes precedence over all other objectives. Because the prime objective of the current preemption methods is to clear the crossing, secondary objectives such as safe pedestrian crossing time and minimized delay are given less consideration or ignored completely. Consequently, state-of-the-practice strategies may cause serious pedestrian safety and efficiency problems at IHRGCs. Therefore, there is a definite need for research on how to improve traffic signal preemption strategies. An important element of preemption strategy is detection of trains and prediction of arrival times. However, because of the limitations of current detection technologies, estimation algorithms, etc., there is a wide range in these warning times. In this dissertation, a new train-arrival prediction algorithm was developed using detection equipment located farther upstream from the HRGC. The state-of-the-art transition preemption strategy (TPS) was developed to ensure that as preemption is initiated by approaching trains, the signal display does not change in a manner that endangers either pedestrians or drivers. However, because it does not account for the variability of predicted train arrival times, there is still a possibility of failure. Therefore, a new transition preemption algorithm that is specifically designed to improve intersection performance while maintaining or improving the current level of safety is developed. This dissertation developed a preemption strategy (TPS3) that uses better train arrival time estimates to improve the safety and efficiency of IHRGCs. The approach was simulated on a test bed in College Station, Texas, and it was concluded that the new TPS improves the safety and operation of intersections near highway-railroad grade crossings.

L’extensa implantació del control digital als entorns industrials, científics, comercials, professionals i domèstics ha revelat, d’ençà dues dècades, la gran sensibilitat d’aquests dispositius davant sobtats i breus descensos de tensió al subministrament elèctric de xarxa: aturades de plantes a processos productius, re – arrancades a processadors i sistemes de telecomunicació, etc.; i la causa sol esdevenir aparentment inexplicable pels usuaris. La normalització de les conseqüències, però, pot equivaler a un dia sencer de producció nul•la. L’ínfima correlació mostrada pels fenòmens esmentats amb anomalies al sistema elèctric proper (un client pot patir sèries conseqüències, per bé que el client veí només ha percebut una oscil•lació a l’enlluernat, i tots dos comparteixen la mateixa escomesa) sumada amb l’absència contrastada d’interrupció elèctrica suposà, al començament, un major grau d’incertesa, no només pels consumidors; també per a les empreses elèctriques. Fou necessari analitzar el problema en les seves vessants “microscòpica” i “macroscòpica” per a determinar la causa eficient: registrar la forma d’ona al punt de subministrament afectat i fer l’inventari de tots els incidents al Sistema Elèctric del mateix moment. La causa: els sots de tensió produïts per incidents elèctrics a xarxes remotes respecte el subministrament. Davallades sobtades (entre el 80 i el 10% del valor nominal) i ràpides (entre 10 ms i 1 s) al valor eficaç de la tensió subministrada, sense pas per “Zero”, produïdes, principalment, per curt - circuits perfectament detectats i eliminats a xarxes d’Alta Tensió (AT), molt allunyats de la conseqüència observada. A Catalunya, hom comptabilitzen afectacions davant curt - circuits a les interconnexions amb l’Aragó, Castelló i França. La present Tesi Doctoral estableix: • La metodologia per a modelar el Sistema Elèctric de Potència; • La sistematització del binomi causa (curt - circuit) – efecte (sot de tensió); • La personalització estadística de risc pel sot de tensió segons comarques; • Un sistema de protecció eficaç per a limitar la durada dels sots. La metodologia ha estat enfocada a la utilització sistemàtica, tal que per a cada curt - circuit esdevingut a la xarxa AT es pugui establir, en temps real, las capçaleres de subministrament afectades pel sot de tensió, així com la magnitud i la durada del mateix. L’entorn d’aplicació triat ha estat el Sistema Elèctric de Catalunya, per bé que la metodologia i sistemàtica són exportables, de forma natural, a qualsevol altre sistema elèctric trifàsic de corrent altern. / La implantación masiva del control digital en entornos industriales, científicos, comerciales, profesionales y domésticos ha puesto de manifiesto, durante los últimos veinte años, la gran sensibilidad de los mismos ante súbitos y breves descensos de tensión en la alimentación eléctrica procedente de la red: paradas de planta en procesos productivos, re – arranques en procesadores y sistemas de telecomunicación tienen lugar; y la causa de los mismos suele ser aparentemente inexplicable para los usuarios. La normalización de las consecuencias, en ocasiones, equivale a un día de producción nula. La escasa correlación mostrada por dichos fenómenos con anomalías en el sistema eléctrico cercano (un cliente padece consecuencias serias, mientras que el cliente vecino solamente ha percibido una oscilación en el alumbrado y ambos se alimentan del mismo tramo eléctrico) sumada con la ausencia contrastada de interrupción eléctrica supuso, en los inicios, un mayor grado de incertidumbre tanto para los consumidores como para las empresas eléctricas. Fue necesario analizar el problema a nivel “microscópico” y “macroscópico” para determinar la causa eficiente: registrar la forma de onda en el punto de suministro afectado y revisar todos los incidentes habidos en el Sistema Eléctrico en dicho instante. La causa: los huecos de tensión producidos por incidentes eléctricos en redes alejadas del suministro. Descensos súbitos (entre el 80 y el 10% del valor nominal) y rápidos (entre 10 ms y 1 s) en el valor eficaz de la tensión suministrada, sin paso por “cero” de la misma, producidos, principalmente, por cortocircuitos perfectamente detectados y eliminados en redes de Alta Tensión (AT), y situados muy lejos de la consecuencia observada. En el caso de Catalunya, se han contabilizado afectaciones ante cortocircuitos en interconexiones con Aragón, Castellón de la Plana y Francia. La presente Tesis Doctoral establece: • La metodología para modelar el Sistema Eléctrico de Potencia; • La sistematización para el binomio causa (cortocircuito) – efecto (hueco); • La personalización del riesgo estadístico de hueco vs. comarcas; • Un sistema protectivo eficaz para limitar duración de los huecos. Dicha metodología se ha orientado a la utilización sistemática, tal que para cada cortocircuito que tenga lugar en la red AT pueda establecerse, en tiempo real, las cabeceras de suministro afectadas por hueco de tensión, la magnitud y la duración del mismo. Como entorno de aplicación, se ha utilizado el Sistema Eléctrico de Catalunya, si bien la metodología y sistematización son exportables, de forma natural, a cualquier otro sistema eléctrico trifásico de corriente alterna. / The massive introduction of digital control in industrial, scientific, commercial, professional and domestic environments has revealed, over the last twenty years, the great sensitivity of them to sudden and short voltage dips in the electrical power grid: shutdowns of productive process plants, re - starts of processors and telecommunications systems take place, and the cause of them is often apparently inexplicable to the users. The normalization of the consequences sometimes is equivalent to a day without production. The weak correlation shown by these phenomena with anomalies in the nearby electrical system (i.e. in the same portion of a common distribution network, a customer may suffer serious consequences, while the adjacent customer has only percept a swing in the lighting) together with the absence of electrical power interruption represented, in the beginning, a great degree of uncertainty for both consumers and utilities. It was necessary to analyze the problem at the "microscopic" and "macroscopic" levels to determine the efficient cause: record the waveform at the affected plants and review all the disturbances occurred in the Power System at the same instant of time. The cause: voltage dips caused by electrical disturbances away from the supply. Sudden decreases (between 80 and 10% of the nominal value) and fast (between 10 ms and 1 s) in the supplied rms voltage, produced mainly by short-circuits perfectly detected and eliminated in High Voltage (HV) networks, and located far away from the observed consequence. In the case of Catalonia, affectations due to short-circuits in interconnects with Aragon, Castellón de la Plana and France have been recorded. This thesis provides: • A methodology useful to model the Power System; • A systematic analysis for cause – effect: from short – circuit to voltage dip; • A particularization voltage dip statistic risk for each county; • A reliable protective system to ensure time – limitation for voltage dips. The presented methodology is oriented to the systematic use, such that for every short - circuit that takes place in the HV network, the magnitude and duration of voltage dips that appear in the distribution can be established in real-time. As the application framework, the Catalan Power System is used, although the methodology and systematization are exportable, to any other alternating three-phase power system.