By using an automatic system to advise rail traffic managers, it is possible to limit the consequences of disruptions on the railways. That is the claim by Andrea D'Ariano who has obtained his PhD on the subject at TU Delft. Netherlands Railways (NS) is looking for ways to improve the punctuality of its trains. One possibility is to streamline the sequence of events during breakdowns and delays.

A single delayed train can lead to many others being delayed too. At present, when there is a disruption or breakdown, it is rail managers who decide which trains are given priority and which are diverted, for example. There is no particular strategy for this - the managers take their decisions on an ad hoc basis.

ROMA
TU Delft PhD student Andrea D'Ariano has examined this matter in a much more structured way. Using mathematical models and algorithms, he has developed ROMA - Railway traffic Optimization Means of Alternative graphs. This is an automated system that can assist traffic managers in their tasks, highlighting optimum routes and sequences, and preventing them from taking decisions that turn out not to be very effective. In simulated studies, the use of ROMA led to fewer and shorter delays.

This does not mean, however, that ROMA will shortly be used by the railways. In order for it to be able to make reliable forecasts, it is necessary that every piece of up-to-date information regarding the trains be available to the last detail on a continuous basis. This is not yet the case. However, it is expected that more and more trains will be fitted with GPS, and this will lead to an improvement in the provision of information.

Schiphol
In spite of this drawback, D'Ariano believes that NS and ProRail are interested in the system and in developing it further. "For them it is a relatively inexpensive means of improving levels of punctuality." The development of a system like ROMA is part of a trend of increasing "dynamic traffic management." This strategy gives rail managers a little more flexibility, and can already be seen at Schiphol station in a very modest way, where the decision as to which platform a train enters the station is taken only at the last moment.