Modern Transit Systems Research Articles

Electrical Safety and Stray Current Protection With Platform Screen Doors in DC Rapid Transit

Modern transit systems are equipped with platform screen doors (PSDs) that represent a new element introduced in electrical safety and stray current protection scenarios. Passengers may interact with PSDs and platforms while boarding, leaving, and waiting for trains. Typical contractual requirements and applicable standards are discussed, identifying touch voltage scenarios suitably defining electrical circuits and parameters. The dc voltage limits are at all clear and unambiguous in the range of relevant touch voltage values. The evaluation of exposure is, thus, carried out with the help of body impedance and body current models. Solutions are then discussed for the protection of PSDs and passengers, including stray current limitations as a constraint. A novel PSD bonding arrangement is proposed, which reconciles insulation for utmost electrical safety level and bonding for traction fault protection.

Effects of new bus and rail rapid transit systems – an international review

ABSTRACTCities worldwide are implementing modern transit systems to improve mobility in the increasingly congested metropolitan areas. Despite much research on the effects of such systems, a comparison of effects across transit modes and countries has not been studied comprehensively. This paper fills this gap in the literature by reviewing and comparing the effects obtained by 86 transit systems around the world, including Bus Rapid Transit (BRT), Light Rail Transit (LRT), metro and heavy rail transit systems. The analysis is twofold by analysing (i) the direct operational effects related to travel time, ridership and modal shifts, and (ii) the indirect strategic effects in terms of effects on property values and urban development. The review confirms the existing literature suggesting that BRT can attract many passengers if travel time reductions are significantly high. This leads to attractive areas surrounding the transit line with increasing property values. Such effects are traditionally associated with attractive rail-based public transport systems. However, a statistical comparison of 41 systems did not show significant deviations between effects on property values resulting from BRT, LRT and metro systems, respectively. Hence, this paper indicates that large strategic effects can be obtained by implementing BRT systems at a much lower cost.

Optimizing Pricing Policies in Park-and-Ride Facilities: A Model and Decision Support System with Application

Park-and-ride facilities are of major importance to the attractiveness and operation of modern transit systems because travelers tend to prefer public transportation when they are able to combine the use of these facilities with their private vehicles. Among those elements examined when developing/operating a park-and-ride facility is the pricing policy to be established for its users. Indeed, the pricing policy is among those tools that can aid transportation agencies in managing park-and-ride facilities, by providing incentives or disincentives of parking for various categories of users. This paper contributes to the literature by offering a new approach for obtaining optimal pricing schemes for a parking facility, with respect to its financial viability. In particular, a financial analysis model is combined with a genetic algorithm for determining the optimal pricing parameters for park-and-ride facilities. The model is applied for a shared-use, park-and-ride facility of the Athens metro network in Greece. Results of the computational study indicate that the model can offer near optimal pricing schemes in a short amount of time. Also, a decision support system is developed for incorporating the model in a user friendly computerized framework.

Precast Concrete in the Transit Industry

The paper discusses some of the reasons for the relatively limited use of precast and prestressed concrete in mass transit systems and suggests ways in which the full potential of the material can be attained. Concrete's dynamic and noise abatement characteristics and its architectural adaptability make it an ideal material for guideways. The success of precast concrete's performance, economy, and appearance has been proven on modern transit systems.