Evaluation of green wave policy in real-time railway traffic management

In order to face the expected growth of transport demand in the next years, several new traffic control policies have been proposed and analyzed both to generate timetables and to effectively manage the traffic in real-time. In this paper, a detailed optimization model is used to analyze one such policy, called green wave, which consists in letting trains wait at the stations to avoid speed profile modifications in open corridors. Such policy is expected to be especially effective when the corridors are the bottleneck of the network. However, there is a lack of quantitative studies on the real-time effects of using this policy. To this end, this work shows a comparison of the delays obtained when trains are allowed or not to change their speed profile in open corridors. An extensive computational study is described for two practical dispatching areas of the Dutch railway network.     

Methodology for calculating passenger capacity in bus rapid transit systems: Application to the TransMilenio system in Bogotá, Colombia

Transit textbooks and engineering manuals indicate that the capacity of Bus Rapid Transit –BRT – systems does not exceed 20,000 passengers per hour per direction. The implementation of the TransMilenio BRT System, in Bogotá, Colombia, showed that the systematic combination of multiple platforms at stations, overtaking lanes, level boarding, prepayment, large buses with multiple doors, express and local services, and traffic engineering measures at intersections, allow for very large passenger throughput. Measurements indicate actual throughput of 43,000 passengers per hour per direction with average bus occupancy of 150 passengers per articulated bus, and a commercial speed of 22–24 km/h. According to special formulas developed for the analysis of high capacity BRT corridors, the critical section of TransMilenio has a practical capacity of 48,000 passengers per hour per direction with its existing infrastructure and 150 passengers per bus – 35,000 passengers per hour per direction with 110 passengers per bus. Changes in existing infrastructure, such as additional platforms, higher capacity vehicles, non-grade facilities at critical intersections, among other improvements, may increase the capacity, speed, reliability and quality of service of the system.     

Resistance and seakeeping numerical performance analyses of a semi-small waterplane area twin hull at medium to high speeds

The hydrodynamic analysis of a new semi-small waterplane area twin hull (SWATH) suitable for various applications such as small and medium size passenger ferries is presented. This may be an attractive crossover configuration resulting from the merging of two classical shapes: a conventional SWATH and a fast catamaran. The final hull design exhibits a wedge-like waterline shape with the maximum beam at the stern; the hull ends with a very narrow entrance angle, has a prominent bulbous bow typical of SWATH vessels, and features full stern to arrange waterjet propellers. Our analysis aims to perform a preliminary assessment of the hydrodynamic performance of a hull with such a complex shape both in terms of resistance of the hull in calm water and seakeeping capability in regular head waves and compare the performance with that of a conventional SWATH. The analysis is performed using a boundary element method that was preliminarily validated on a conventional SWATH vessel.     

Implementation of sustainable urban transport in Latin America

Transportation provides vital support to the economic and social development of Latin America cities, but current growth patterns and trends are not sustainable. While non-motorized and public transport modes have the largest shares in passenger transport, there is a strong increase in ownership and use of cars and motorcycles. In Latin America in 2010 there were 2.5 new motor vehicle registrations for every new child being born.