N. van Oort

The impact of scheduling on service reliability: trip-time determination and holding points in long-headway services

This paper presents research on optimizing service reliability of long-headway services in urban public transport. Setting the driving time, and thus the departure time at stops, is an important decision when optimizing reliability in urban public transport. The choice of the percentile out of historical data determines the probability of being late or early, while the scheduled departure time determines the arrival pattern for travelers. A hypothetical line and a case study are used to determine the optimal percentile value for long-headway services without and with holding points. If no holding points are applied, it is shown that the 35-percentile value minimizes the additional travel time to 25 % of the reference situation. In the case of holding, two holding points combined with a 30–60-percentile value yield the best performance: a further reduction of the additional travel time with 60 %.

Using a Rail Simulation Library to Assess Impacts of Transit Network Planning on Operational Quality

This paper will discuss that in order to achieve high operational quality in public transport, ex ante analysis should be made when planning the line network and timetable. This paper presents a Rail Simulation Library which is applicable for light rail and tram systems. This library is the core of a decision support environment to help designers assess the impact of network and timetable design on operational quality, e.g. speed and reliability. This model is used for designing a new light rail connection, RandstadRail, in The Hague. Different scenarios were run to calculate whether the line configuration and timetable were robust and stable. All scenarios consist of several stochastic processes like dwell time, driving time, turning time and waiting time at traffic lights. The model shows the results in both a tabular view as well as in an animation. The Rail Simulation Library proved to be suitable to forecast operations and to support the design of a line network and achievable timetable. By performing an ex ante analysis more robust and stable networks and timetables could be designed, thus facilitating a higher level for operational quality.

The role of infrastructures on public transport service reliability

This research deals with a public transport network design methodology that accounts for reliability and robustness of urban public transport service networks by considering impacts of stochastic events on networks. The study shows the role of infrastructures such as bypasses to improve public transport network robustness. This methodology is applied in a case study: the tram network in city of The Hague. Results show a sensible improvement in network connectivity reliability as well as travel costs.