R. van Nes

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 %.

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.

The impact of route guidance, departure time advice and alternative routes on door-to-door travel time reliability: Two data-driven assessment methods

ABSTRACT Conventional travel time reliability assessment has evolved from road segments to the route level. However, a connection between origin and destination usually consists of multiple routes, thereby providing the option to choose. Having alternatives can compensate for the deterioration of a single route; therefore, this study assesses the reliability and quality of the aggregate of the route set of an origin-destination (OD) pair. This paper proposes two aggregation methods for analyzing the reliability of travel times on the OD level: 1) an adapted Logsum method and 2) a route choice model. The first method analyzes reliability from a network perspective and the second method is based on the reliability as perceived by a traveler choosing his route from the available alternatives. A case study using detailed data on actual travel times illustrates both methods and shows the impact of having variable departure times and the impact of information strategies on travel time reliability.