To wait or not to wait? 
Delay management at hub airports

It is nowadays common that when we fly somewhere we have to take multiple flights, connecting between flights at hub airports. These stops, although in some cases inevitable or even convenient, are always a cause of stress. In case of a delay in the inbound flight, our connection can be compromised, resulting sometimes in a struggle to get a seat in the next flight and in a long wait for the replacement flight.

Airlines try to avoid this hassle by managing the delays as soon as they receive information about them. This usually happens prior to passengers landing at their hub airport. The task is to decide whether to delay subsequent flights in order to wait for the delayed passengers (and bags) or to have the flights departing on time. The decision must be carefully balanced, as imposing a delay on departing flights can have a major impact on the operating schedule of the airline and on the experience of other passengers also booked to the departing flight.

TU Delft helped Kenya Airways (KQ) to develop a decision making tool to support the daily delay management process. The results are promising, suggesting that KQ can reduce up to 10% their current delay related costs and a general reduction of passengers experienced delays.

Jomo Kenyatta International Airport, Nairobi, Kenya (2011) Source:

Figure 1 – Jomo Kenyatta International Airport, Nairobi, Kenya (2011) Source:

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Is Benelux getting any smaller?

We all assume that developments in transport go towards better travel time, more direct connection, increased comfort and reliability..
Well, that’s not always the case.
I am now referring to the Benelux train. In about 10 years of experiences with that train I have seen this link connecting the Netherlands with Belgium running, changing route, getting canceled, substituted by a high speed service, getting re-established, first with longer travel time, then re-installed almost as the original, getting new stations… and future sees even more developments. Meanwhile the two capitals got about half an hour farther away.
What is the story behind it?

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The ‘consolidation in the aviation industry’ is still a challenge for Europe – Dr. Albert Plesman Memorial Lecture

(left) Richard Anderson, CEO of Delta Air Lines lecturing; (right) Dr. Albert Plesman

(left) Richard Anderson, CEO of Delta Air Lines lecturing; (right) Dr. Albert Plesman

When dr. Albert Plesman (1889-1953) became the first president of KLM he was building a company that was planned to be the pride and joy of the Netherlands. After him, virtually all states across the globe followed his vision – sooner or later, they have also created their national flag carriers that could be the symbol of their national identity. However, in the last years, some of these national carrier have disappeared. Some of them have been merged with or acquired by larger (multinational) airlines. This is happening all over the world. And it is now a particular challenge for Europe where multiple small national airlines are facing fearless competition in an open air transport market.

Are smaller European national airlines doomed to disappear? Will we see smaller airlines eventually consolidating into just a small number of large multinational airlines? In the opinion from Richard Anderson, the CEO of Delta Air Lines, this is exactly what will happen.

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More delays as unavoidable effect of competition in railways?

I have been busy trying to reduce delays and delay propagation in railways for a long time now, so it looks quite surprising that somebody might want to increase delays instead. Well, that might be a result of a naive application of the guidelines on competition on the railway market.

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What is the secret of low cost carriers?

Air France – KLM has recently announced, for the third time this year, that they are falling short in their earnings forecast. The French-Dutch carrier, which faced a two-week pilot strike in September, has experienced in the third quarter of 2014 a revenue decrease of about 6.7%, when compared with the same period of the previous year. The damage of the pilot strike on the revenues was initially estimated on 416 million euros but the real costs of transferring passengers to other carriers are still being calculated.

At the same time, easyJet and Ryanair have published positive financial results. EasyJet (Fig. 1) reported a 21.5% rise in annual pre-tax profits, while Ryanair announced that the net profit has rose by 32% in the first half of 2014 . The profit growth of both carriers was supported by a 6% and 4% increase in the number of passengers transported, respectively for easyJet and Ryanair. What is the secret behind these low cost carriers (LCC)? Should Air France – KLM follow their steps and also become a ‘lower’ cost airline? To answer these questions we need to understand what are LCC and how they have emerged.

EasyJet Airbus A319 - Photo: Stefano R. /

Fig 1. EasyJet Airbus A319 – Photo: Stefano R. /

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Will we finally have on time trains?

Train traffic has been always a source of complaints. I mean, trains that are too few. Or when they might have a decent frequency, they might be late. Or when they are on time, they might be too short. Or even, when they are long enough, on time, and every 5 minutes (like most of the cases now in the Netherlands, fairly speaking), then the problem might be that the wireless does not work.

But apart from this psychological aspects, can train traffic possibly be on time, sooner or later? This requires setting up optimized train traffic control, helping the dispatcher in the control room.


That was in a nutshell, the goal of the EU research project Ontime, that just finished a few weeks ago.

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RECREATE – REsearch on a CRuiser Enabled Air Transport Environment

By Dries Visser (TU Delft – Aerospace Engineering)
Project website:

The collaborative project REsearch on a CRuiser Enabled Air Transport Environment (RECREATE) is about the introduction and airworthiness of cruiser-feeder operations for civil aircraft. The RECREATE project, funded through the 7th Framework Programme of the European Commission, is currently being conducted by a consortium comprising ten European partner organizations, including Delft University of Technology. In this project, which started in 2011, so-called cruiser-feeder operations are investigated as a promising pioneering idea for energy efficient long-haul air transport in the second half of this century. In cruiser-feeder operations, feeder aircraft dock to long-haul passenger (cruiser) aircraft and transfer payload and/or fuel to the cruiser, to then return to the nearby feeder base.

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Wat kan de Nederland leren van het buitenland op het gebied van MKBA?

Wat kan de Nederlandse maatschappelijke kosten-batenanalyse praktijk leren van de Deense, Noorse, Britse en Zweedse MKBA-praktijk? Dit is de onderzoeksvraag die centraal stond in de studie ‘MKBA Internationaal’ die ik recentelijk uitvoerde voor het Planbureau voor de Leefomgeving. De volledige studie kunt u downloaden via deze link maar in deze blog zal ik de belangrijkste lessen die volgen uit deze studie op een laagdrempelige manier op een rijtje zetten:

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Huarong Zheng (Transport Engineering and Logistics/3ME/TU Delft) first prize winner at Rotterdam Smart Port Event

On October 2, 2014, the smart port event took place, sponsored by Port of Rotterdam and with no less than 32 contributions showcasing research results in port-related areas, from Groningen, Delft, Rotterdam, and various Belgian universities.

Each contribution resulted in a poster, prepared by a PhD student who is taking care of the research; research was at very different stages, and with a quite wide focus (from historical studies to geography, emission trading, optimization algorithms). Among the goals are facilitating the interaction between the port research and the industry, represented by logistic companies and the Port of Rotterdam Authority.

One of the nice features of the event was the awarding of two prizes, one academic and one for the best poster, chosen by the public. Bart van Riessen (PhD student at Erasmus University and Transport Engineering & Logistics at TU Delft; supervisors Rudy Negenborn and Rommert Dekker) received the public prize for his work on “decision support for synchromodal transport“.

Moreover, Huarong Zheng (PhD student at Transport Engineering & Logistics at TU Delft; supervisors Rudy Negenborn and Gabriel Lodewijks) was the first prize winner, to her biggest surprise. “I did not expect this at all”, she said. She started her PhD almost 2 years ago, coming from the Chinese city of Wuhan, with a China Scholarship Council grant. She is happy to have received the first prize, which comes with 2500 euros contribution. What is the key feature of her approach? Continue reading

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Substitutie door elektrisch fietsen

Elektrische fietsen zijn de succesvolste variant van elektrische voertuigen en ze verkopen zichzelf!

Elektrische auto’s hebben allerlei beperkingen ten opzichte van de traditionele brandstofauto. Belangrijkste nadeel is wel dat de actieradius veel kleiner is, ergens tussen de 80 en de 150 kilometer en de meeste mensen durven niet tot de laatste kilometer door te rijden, dus de actieradius is feitelijk nog kleiner. Verder is het laden nogal langdurig en laadpalen zijn schaars. Hoewel elektriciteit veel goedkoper is dan benzine, zijn de aanschafkosten nogal hoog, dus een flinke financiële stimulans van de overheid is noodzakelijk.

Elektrische fietsen daarentegen hebben veel voordelen. Het belangrijkste verschil met elektrische auto’s is dat ze de actieradius voor de doorsnee fietser niet verkleinen, maar juist vergroten. Laten we even van dichtbij kijken.

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