ABSTRACT In the last decades, numerous footbridges experienced excessive displacements in the lateral direction of passage, cases such as Millennium, Solferino and Toda among the most known, which caused that the pedestrian have difficulties in using these structures and often requiring expensive repairs. This research studies the problem of the lateral vibrations produced by the pedestrian crossing in footbridges known as the phenomenon of synchronous lateral excitation through the lateral vibration analysis of the walkway adjacent to the “Rayitos de Sol” footbridge, which crosses the Rímac river, near the center of Lima. This particular footbridge had presented excessive lateral vibrations from its construction in 2006, until 2016 when this research was developed. This particular situation constituted an ideal state for the development of experimental work. Particular details of the phenomenon of synchronous lateral excitation were found during this research. first, that the pedestrian density is directly proportional to the probability of occurrence of the phenomenon, second, that the phenomenon is cyclic in nature and the occurrence of a maximum acceleration from which the pedestrian breaks its path and the phenomenon decays.

RESUMEN En las últimas décadas, numerosos puentes peatonales experimentaron vibraciones excesivas en la dirección lateral, casos como el Millenniun, Solferino y Toda entre los más conocidos, causando en los peatones dificultades para cruzarlos y muy frecuentemente requiriendo caras reparaciones. Esta investigación estudia el problema de las vibraciones laterales producidas por el cruce de peatones en puentes peatonales conocido como Fenómeno de excitación sincrónica lateral a través del análisis de vibración lateral de la pasarela adyacente al puente peatonal “Rayitos de Sol”, que cruza el rio Rímac, cerca al centro de Lima. Este puente en particular presentaba excesivas vibraciones laterales desde su construcción en 2006 hasta el momento que fue desarrollada este estudio en 2016. Esta situación particular constituyó un estado ideal para el desarrollo del trabajo experimental. Durante esta investigación fueron encontrados detalles particulares del fenómeno de excitación sincrónica lateral, el primero que la densidad peatonal es directamente proporcional a la probabilidad de ocurrencia del fenómeno, el segundo que el fenómeno es de naturaleza cíclica y la ocurrencia de una aceleración máxima a partir de la cual el peatón rompe su paso y el fenómeno decae.

Vehicle fuel consumption and emission rates in Kuwait have increased considerably over recent decades, and are now causing health and economic problems. A three-lane smart roundabout is a new and innovative design idea that can help to mitigate these issues. The smart roundabout was designed with a dedicated exit lane on the right side of each entryway, and a U-turn path connecting each adjacent entry and exit road. Both features permit vehicles to turn in specific directions without needing to enter the roundabout itself. Underground tunnels were designed for pedestrian and cyclist use. The objective of this study was to measure the impact of a smart roundabout on vehicle fuel consumption and on emissions of carbon dioxide, carbon monoxide, nitrogen oxides, and hydrocarbons. These results were then compared with those of a traditional roundabout and of a light-signalised intersection. Two light-signalised intersections with different traffic volumes were chosen for this study and simulated in their present state, as replaced by traditional roundabouts; and as replaced by smart roundabouts using the SIDRA 6.0 software. The smart roundabout allowed traffic to proceed with minimal delay and idling time, significantly reducing vehicle fuel consumption and emissions in comparison with a traditional roundabout or light-signalised intersection. Furthermore, the smart roundabout allowed pedestrians and cyclists to move safely through the intersection without interacting with vehicular traffic.

Voertuig brandstofverbruik en emissietempo's in Koeweit het aansienlik verhoog oor die laaste paar dekades en veroorsaak gesondheid- en ekonomiese probleme. A drie-laan slim verkeersirkel is 'n nuwe en innoverende ontwerp wat kan bydrae tot die verligting van hierdie kwessies. Die slim verkeersirkel is ontwerp met 'n toegewyde uitgangslaan aan die regterkant van elke ingang en 'n U-draai baan wat naburige ingang- en uitgangslane verbind. Beide kenmerke laat voertuie toe om in spesifieke rigtings te draai sonder om die verkeersirkel te betree. Ondergrondse tonnels is gebruik vir voetgangers en fietsryers. Die doel van die studie is om die impak van so 'n slim verkeersirkel op die brandstofverbruik en uitlaat van koolstofdioksied, koolstofmonoksied, stikstofoksiede en hidrokoolstowwe te meet. Die resultate is dan met dié van 'n tradisionele verkeersirkel en 'n verkeersligkruising vergelyk. Twee verkeersligkruisings met verskillende verkeervolumes is gekies vir hierdie studie en in hul huidige toestand, met tradisionele verkeersirkels en met die voorgestelde slim verkeersirkel, met behulp van die SIDRA 6.0 sagteware gesimuleer. Die slim verkeersirkel het die verkeer met minimale vertraging en luier tyd laat vloei wat die brandstofverbruik en uitlaatgasse noemenswaardig laat verminder het. Verder het die slim verkeersirkel voetgangers en fietsryers met veilige deurgang deur die kruising verskaf sonder om met die padverkeer te meng.

Geography as support of public space and infrastructure: modest targeted interventions on an urban riverbed result in a large pedestrian and cycle promenade. Its urban and territorial magnitude reminds of Le Corbusier's synthesis for his Latin American urban plans.

La geografía como soporte de espacio público e infraestructura: el cauce de un río urbano y pequeñas intervenciones puntuales dan lugar a un paseo continuo para rodados, con una dimensión urbana y territorial que recuerda la síntesis de los planes urbanos de Le Corbusier para Latinoamérica.