El texto completo de este trabajo no está disponible en el Repositorio Académico UPC por restricciones de la casa editorial donde ha sido publicado. / The continuous flow intersections (CFI) increase the operational capacity of road systems with congestion problems, by using shared lanes located at the access points before the intersection. However, the CFI presents road safety risks that increase the likelihood of vehicle collision. This article proposes a geometric design composed of raised delineators at a traffic-light intersection, whose objective is to eliminate the points of primary conflicts caused by the left turns of the vehicles. To do this, a study was conducted to identify the different maneuvers present in a wide cross-type intersection in a commercial area located in the city of Lima. A total of 3219 vehicles was collected, of which 561 vehicles turned left demonstrating the high density of this type of maneuver. The effectiveness of the proposed design is validated using a microsimulation in the Vissim program. The results show that it was reduced from 58 to 8 points of conflict, increasing operational capacity by 34.97%. Finally, the risks caused by CFI decreased by 83%. / Revisión por pares

Major crossroads are designed to facilitate the conflicting movements of numerous vehicles in a manner that is both safe and efficient. Accesses located within the functional areas of major crossroads add complication to intersection activity due to additional conflicts arising from ingressing and egressing movements at the accesses. In this research, the impact of accesses on crashes within major crossroad functional areas was analyzed. Specifically, the effects of access spacing within functional areas and access setback from intersections were addressed. In order to conduct the analysis, the functional areas of 159 signalized major arterial crossroads across the state of Utah were examined. A database was built containing the frequency, type, and severity of functional area crashes as well as the intersection and roadway characteristics within the functional area. Statistical analyses were conducted to determine the influence of accesses in intersection functional areas on functional area crashes. The statistical analyses show that the existence of accesses within the functional areas was correlated with increased crashes and crash severity costs. In particular, an increase in commercial access density was associated with increases in crash totals, crash rates, and rear end crashes in intersection functional areas. The analyses also showed that study site intersections meeting Utah Department of Transportation (UDOT) corner clearance standards exhibited fewer right angle crashes and lower crash severity costs. Finally, intersections that prohibited all unsignalized access had lower crash totals, crash rates, right angle crash totals, and rear end crash totals than intersections that allowed some unsignalized access.

Left-turning maneuvers are considered to be the highest risk movements at intersections and two-thirds of the crashes associated with left-turns are reported at signalized intersections. Left-turning vehicles typically encounter conflicts from opposing through traffic. To separate conflicting movements, transportation agencies use a protected-only phase at signalized intersections where each movement is allowed to move alone. However, this could create delays and thus the concept of a protected-permissive phase has been introduced to balance safety and delays. However, the permissive part of this phasing scheme retains the safety concerns and could increase the possibility of conflicts resulting in crashes. This research developed a model that can predict the number of crashes for protected-permissive left-turn phasing, based on traffic volumes and calculated conflicts. A total of 103 intersections with permissive-protected left-turn phasing in Kentucky were simulated and their left-turn related conflicts were obtained from post processing vehicle trajectories through the Surrogate Safety Assessment Model (SSAM). Factors that could affect crash propensity were identified through the Principal Component Analysis in Negative Binomial Regression. Nomographs were developed from the models which can be used by traffic engineers in left-turn phasing decisions with enhanced safety considerations.

Las ciudades altamente congestionadas requieren de una óptima gestión de la movilidad urbana. Muchas de estas ciudades se caracterizan porque su infraestructura vial no va acorde con su demanda vehicular, como es el caso de la ciudad de Lima. Por consiguiente, se debe priorizar el desarrollo de la infraestructura vial, ya que existen por ejemplo intersecciones amplias que presentan gran cantidad de puntos de conflicto. En efecto, reducen la capacidad operacional y el nivel de servicio de la intersección. Esta investigación tiene como objetivo reducir los puntos de conflicto y el tiempo de cruce en intersecciones amplias tipo cruz, en base a la Metodología de Flujo Continuo (CFI, por sus siglas en inglés) con delineadores elevados (bolardos compuestos) y detectores (sensores) a fin de mejorar la capacidad y seguridad operacional de la intersección. El objeto de estudio de la presente investigación se encuentra en una zona comercial ubicada entre la Avenida República de Venezuela con la Avenida Aurelio García y García, Lima. Los movimientos vehiculares de giro a la izquierda son los que afectan el rendimiento de las intersecciones señalizadas. Por tanto, se recolectaron 3219 vehículos en total, de los cuales 561 vehículos giraron a la izquierda demostrando así la alta densidad de este tipo de maniobras. La efectividad del diseño propuesto se valida empleando una microsimulación en el software Vissim. Los resultados obtenidos muestran los puntos de conflictos tipo cruz se redujeron a 8 puntos con el modelo propuesto frente al estado actual, el cual posee 58 puntos de conflictos tipo cruz. Por otro lado, el tiempo promedio de cruce de los vehículos disminuyó en 4.20 y 9.79 segundos en la fase 1, debido al rediseño de la geometría de la intersección. En efecto, la capacidad operacional aumentó en 33.85%, ya que el aforo vehicular con el nuevo ciclo semafórico de 150 segundos es de 431vehículos con respecto a los 322 vehículos que se tenía con el modelo anterior. Finalmente, los riesgos de colisiones posteriores y laterales se reducen mediante el uso de delineadores elevados en un 83%. / Highly congested cities require optimal management of urban mobility. Many of these cities are characterized because their road infrastructure does not match their vehicular demand, as is the case in the city of Lima. Therefore, the development of road infrastructure should be prioritized, since there are, for example, wide intersections that present a large number of conflict points. In effect, they reduce the operational capacity and service level of the intersection. This research aims to reduce conflict points and crossing time at wide cross-type intersections, based on the Continuous Flow Methodology (CFI) with elevated eyeliners (composite bollards) and detectors (sensors) in order to improve the capacity and safety of the intersection. The object of study of the present investigation is in a commercial area located between avenue Republica de Venezuela with avenue Aurelio Garcia y Garcia, Lima. The left-turn vehicular movements are those that affect the performance of the signposted intersections. Therefore, 3219 vehicles were collected in total, of which 561 vehicles turned left demonstrating the high density of this type of maneuver. The effectiveness of the proposed design is validated using microsimulation in the Vissim software. The results obtained show the points of cross-type conflicts were reduced to 8 points with the proposed model compared to the current state, which has 58 points of cross-type conflicts. On the other hand, the average crossing time of the vehicles decreased by 4.20 and 9.79 seconds in phase 1, due to the redesign of the intersection geometry. In fact, the operational capacity increased by 33.85%, since the vehicle capacity with the new traffic light cycle of 150 seconds is 431 vehicles with respect to the 322 vehicles that had the previous model. Finally, the risks of posterior and lateral collisions are reduced by the use of elevated eyeliners by 83%. / Tesis

This thesis builds on previous work on an Institute of Roads FAST VUT dealing with modifications of road I/43 Brno – Svitavy. A conversion of the existing temporary three leg single lane roundabout to egg turbo roundabout with four legs, is proposed there, in accordance with local plan of Lipůvka. The intersection of road I/43 and II/379 can be characterized by large congestions in the morning peak hours during weekdays and afternoon peak hours on Saturday and Sunday. That is the reason for implementation of capacity assessment of designed turbo roundabout and comparison with current situation. Construction of fourth leg is motivated by the planned expansion of residential area and the development of industrial zone on the south-western outskirts of the village and rerouting of the county road II/379 out of built-up area as well. Road I/43 is an important thoroughfare north of Brno, so it is obvious effort to eliminate the bottlenecks on the route. The thesis also includes a theoretical introduction dealing with the design of turbo roundabouts abroad.