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Transportation Research Procedia 8 (2015) 72 – 79

European Transport Conference 2014 – from Sept-29 to Oct-1, 2014

New insights in resistance to interchange
Bart de Keizera,*, Marco Kouwenhovenb, Freek HofkercaNederlandse Spoorwegen (NS), P.O. Box 2025, 3500 HA Utrecht, The NetherlandsbSignificance, Koninginnegracht 23 2514 AB The Hague, The Netherlandsc
ProRail, Moreelsepark 3 3511 EP Utrecht, The Netherlands

Abstract
Train passengers experience an interchange between trains in their trip as a nuisance. To model this resistance, a penalty is
usually added in the calculation of the perceived journey time. For many years, NS and ProRail used a fixed penalty of 10
minutes per interchange for rail trips in the Netherlands. This penalty was based on expert-judgement.
A stated preference survey in 2011 [De Keizer et al, 2012, customer resistance to interchanges, ETC Glasgow] demonstrates that
customers experience a much higher penalty than 10 minutes. The penalty also strongly differs with characteristics of theirtransfer, like transfer time, frequency of the connecting service and whether the transfer is cross platform or not. Recently, the SPdata have been re-analyzed, based on the recommendations of an audit on the 2011 work. This new analysis shows that areference penalty is 23 minutes (including 2 minutes transfer time), which is more than twice as high as the current value.
However, under certain optimal circumstances, the penalty can be lower than 14 minutes. Comparing the findings with earlier
results and findings from international literature shows a similar dependence between punctuality, the connection time and thefrequency of the connecting train in all studies. The added value of the new survey is a more detailed analysis of the importanceof the various aspects of interchanges between trains. The outcomes of the new analysis have been compared with real-world
data. This comparison showed that using the new values led to a much better fit with reality. For example, growth rates ofvarious direct connections to Schiphol Airport were 30-100% higher in reality than had been predicted with the fixed 10 minutes
penalty . Applying the new differentiated penalty led to a forecast with a maximum deviation of only 15% compared with thereal-world figures.
© 2015 Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license© 2015 The Authors. Published by Elsevier B. V.
(http://creativecommons.org/licenses/by-nc-nd/4.0/).
Selectionandpeer-review
peer-review
underresponsibilityof Association
for European
under
responsibilityof Association
for European
TransportTransport.
Selection andKeywords: interchange, resistance, stated preference, railways, customers experience.

* Corresponding author:
E-mail address: Bart.deKeizer@ns.nl

2352-1465 © 2015 Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license(http://creativecommons.org/licenses/by-nc-nd/4.0/).
Selection and peer-review under responsibility of Association for European Transport
doi:10.1016/j.trpro.2015.06.043

Bart de Keizer et al. / Transportation Research Procedia 8 (2015) 72 – 79

1. Introduction
Train passengers experience an interchange between trains as a nuisance. To model this resistance, a penalty is
usually added in the calculation of the perceived journey time. For many years a fixed penalty of 10 minutes perinterchange was used for rail trips in the Netherlands. This penalty was based on expert-judgment.
A stated preference survey conducted by NS in 2011 [De Keizer et al, 2012] demonstrated that customers
experience a penalty which is much higher than 10 minutes. The penalty also strongly varies with characteristics ofthe transfer, such as transfer time, frequency of the connecting service and whether the transfer is cross platform ornot. In the Netherlands NS, the operator of the core rail service (whose market share in Passenger-Rail-Kilometres isapp. 90%), and ProRail, the infrastructure provider, work closely together in improving the quality of the timetable.
Because of this common interest, NS and ProRail decided to use these new insights for future timetabledevelopment. Before that, Steer Davies Gleave (SDG) was commissioned to conduct an audit on the study andSignificance was asked to improve the model estimations following the recommendations of SDG.
This paper discusses the re-analysis and compares the findings with earlier results and findings from international
literature. It also shows the comparison between the model outcomes with the real-world observations and discusses
its application in demand forecasting models.
2. Discussion of re-analysis
The 2011 SP survey contained two experiments. In the first, respondents were asked to choose between two travel
alternatives. Both with one interchange but different characteristics of the interchange. Each alternative wasdescribed by its travel time, the transfer time and the type of interchange (cross-platform, cross-station withescalators, cross-station without escalators). In the second experiment, the number of interchanges between thealternatives varied from 0 to 2 interchanges. The alternatives were described by travel time, transfer time, number ofinterchanges, possible additional waiting time when missing a connection and cost of the trip. The type ofinterchange was not presented in the second experiment.
We estimated utility functions to model the choices of the respondents (Ben-Akiva and Lerman, 1985). Data fromboth experiments were pooled using appropriate scale factors.
We assumed a linear disutility for travel time, travel cost and possible additional waiting time. For the number ofinterchanges and the type of interchange, we estimated constant disutility factors. For the transfer time, a linear
utility term did not fit the data. A transfer time of 5 minutes was clearly preferred above a shorter transfer time (2minutes) or a longer transfer time (8 minutes or higher), so a 5-minute interchange is viewed as optimal by the
respondents (Figure 1). Therefore, we assumed a linear declining disutility function for interchanges between 2 and5 minutes, and an increasing disutility for transfer times above 5 minutes.
We estimated separate utility functions for three travel purposes: commuting & business, education and other. A
general-purpose model was estimated on data from all respondents, using weight factors to correct for an unbalancein the distribution over the purposes in the sample. Error margins were corrected for the panel structure of the data
(using a Jackknife procedure, see Miller 1974). Final results are presented in Table 1. All estimated coefficients are
divided by the travel time coefficient, so that they can be presented in equivalent travel time minutes.
From these modelling results, we draw the following conclusions:x The value of travel time is 6.77 minutes per euro, or 8.86 euro per hour. This is consistent with 9.25 euro perhour, which is the official value from a nation-wide value-of-travel-time survey in the Netherlands (Significanceet al. 2012; Kouwenhoven et al. 2014).
x The value of one minute transfer time (above 5 minutes) is equivalent to 1.67 minutes of travel time. This is
nicely within the range of 1.2 – 2.5 minutes for interchange multiplier factors used in other countries (Wardman2014). The optimal transfer time is 5 minutes, as can be seen from Figure 1.
x Travelers have a strong preference for a trip without interchanges. A direct connection is valued at 22.63 minutes
less compared to a connection with one interchange but otherwise similar characteristics. It should be noted that
we assume this interchange to be cross-platform with a transfer time of 2 minutes and a possible extra waitingtime of 15 minutes (when the connecting train is missed due to delays).

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x Different interchange characteristics will result in a different valuation: the value of a direct connection compared
to a trip with one interchange with 5 minutes transfer time and 10 minutes possible extra waiting time is only
13.36 minutes.
x One minute of possible additional waiting time is valued at 0.72 minutes of travel time, which seems reasonable.
x A cross-station interchange is valued at an equivalent of 7.22 minutes travel time increase compared to a crossplatform interchange. No significant difference was found between a cross-station interchange with and without
escalators. A more precise analysis revealed that the penalty is about 6.4 minutes for people travelling without
luggage or with only a small bag, and 13 minutes for people travelling with heavy luggage.
Table 1: Final model results and t-ratios. All model coefficients are expressed in equivalent travel time minutes. Note that the uncertainties in theinterchange coefficients should be doubled (i.e. t-ratios should be halved) due to unclear specification of the SP, see text.
Purpose:(In equivalent travel time)ALL

COMM./BUS.

OTHER

EDUCATION

Coeff.

t-ratio

Coeff.

t-ratio

Coeff.

t-ratio

Coeff.

t-ratio

6.77(10.8)

3.83

(7.8)

11.95

(10.9)

7.64

(3.2)

0

(-)

0

(-)

0

(-)

0

(-)

For each minute between 2 – 5 min.

-1.89(-4.4)-0.77(-2.5)-4.43(-6.6)-1.85(-1.3)For each minute above 5 minutes

1.67

(9.1)

1.68

(12.9)

1.29

(5.1)

1.74

(2.9)

0*

-22.63(-10.2)-18.88(-9.6)-31.13(-9.5)-20.07(-3.6)

1

0

(-)

0

(-)

0

(-)

0

(-)

2*

15.62

(10.7)

13.60(10.7)

21.15(10.0)

14.47

(3.7)

TRAVEL COST
For each Euro
TRANSFER TIME
Transfer time = 2 minutes

NUMBER OF INTERCHANGESPOSSIBLE EXTRA WAITING TIME
Possible waiting time = 15 minutes

0

(-)

0

(-)

0

(-)

0

(-)

For each minute different from 15 min.

0.72

(7.3)

0.59

(7.2)

1.03

(7.6)

0.58

(2.1)

TYPE OF INTERCHANGE
Cross-platform

0

(-)

0

(-)

0

(-)

0

(-)

Cross-station

7.22

(6.4)

5.31

(7.4)

11.86

(7.4)

7.48

(1.9)

Compared to the previous analysis (De Keizer et al. 2012) we have combined the data from the two experiments
in a different way: amongst others, we used a uniform base level for a single interchange. Previously, the travel timecoefficient depended on the trip duration but the evidence for this in the data was not convincing. We included in
our final model only coefficients that are significant and are relevant for the implementation (see next section), allother coefficients have been removed. These changes were made following the recommendations from the external
auditor (Steer Davies Gleave).
Furthermore, we looked into the uncertainties of the final estimated coefficients. On top of the estimation error
margins, we believed that the uncertainty in the transfer penalties should be doubled since some of the attributes in
the SP were not clearly specified. Specifically, in the second experiment, it was not specified whether theinterchange was cross-platform, or cross-station.

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Bart de Keizer et al. / Transportation Research Procedia 8 (2015) 72 – 79

Fig. 1: Additional penalty for an interchange with a transfer time of more than 2 minutes

3. Recommended values for interchange penalties
Table 2 summarizes the set of interchange penalties in the perceived journey time. The interchange penalty has
been constructed for an arbitrarily chosen case:1.
Cross-platform interchange
2.
Transfer time of 2 minutes
3.
“Possible additional waiting time by missing the interchange” of 15 minutes
4.
Travelling with ‘average’ luggage
For this situation, the transfer penalty is equal to 23 minutes (including 2 minutes transfer time). For othersituations, the penalty can be calculated by comparing its characteristics with these above. For every deviation of thecharacteristics a supplement or reduction on the value of the interchange penalty is made (see table 2). The starting
value plus or minus the values of the deviations make the complete interchange penalty.
Figure 1 shows the relationship between the transfer time and the additional penalty for a transfer time of morethan 2 minutes. The negative values between 2 and 8.5 minutes transfer time mean that the interchange penalty inthis range is lower than for an interchange with a transfer time of 2 minutes. From a customer’s point of view the
optimal transfer time is 5 minutes.
Table 2: recommended values for interchange penalties
Resistance factor

Perceived journey time by trip
purpose (minutes)

Interchange penalty (transfer time included) for a cross platform interchange with atransfer time of 2 minutes and a possible additional waiting time of 15 minutes

23

Cross-station interchange (instead of cross-platform)+7

Travelling with heavy luggage+7

Travelling with no luggage / only light luggage-1

Transfer time

See figure 1

Possible additional waiting time by missing an interchange

See table 3

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Although the model estimation did not result in a dependency because of the lack of longer transfer times in the
SP design, it is very likely that the resistance for the possible additional waiting time depends on the plannedtransfer time of the interchange. After all, the likelihood of missing the connection decreases by the increase of theplanned transfer time. Based on expert-judgment of NS and ProRail experts a dependence between the tworesistance factors has been implemented in the application model: the resistance for possible additional waiting time
is constant up to 8 minutes and decreases to zero between 8 and 15 minutes transfer time as is shown in Table 3.
Table 3: Dependency between ‘Possible additional waiting time’- penalty and the transfer time
‘Possible additional waiting time’- penalty per minute
0,72
0,72 * (15 – Transfer time) / 7
0Transfer time (minutes)<= 8
Between 8 and 15>= 15

4. Comparison of the findings with international literature
We did not find any literature with a similar detailed analysis of the importance of various aspects ofinterchanges between trains. However, the average height of the new penalty seems to be in the range ofinternational findings. In general, the new value corresponds better with the results from other studies than thepreviously used fixed value of 10 minutes penalty (excluding transfer time).
In the Passenger Demand Forecasting Handbook (PDFH) the interchange penalties are split by distance band andticket type. An interchange in a trip with a distance of 25 km has a penalty of 15 minutes for full fare and reduced
tickets and a penalty of 10 minutes for season tickets. For a distance of 160 km it increases to 40 minutes for full
fare and reduced tickets and 26 minutes for seasonal tickets. The transfer time has been excluded from thesenumbers. The range between 10 and 40 minutes is in line with the range in our study: quite common values are
between 8 and 35 minutes. The difference between the ticket types full fare/reduced and seasonal is largely
consistent with the difference in trip purposes social-recreational and commuting.
In a research of MVA (1985) a cross-station interchange (instead of cross-platform) was valued at 9 minutes.
That’s comparable to the 7 minutes extra penalty for cross-station penalties in this study.
In Wardman, M., & Hine, J. (2000) several studies are mentioned about the impact of a guaranteed connection on
the interchange penalty. A MVA study (1987) of the Network South East suburban services shows an interchange
penalty of 13 minutes if the connection is guaranteed. If it is not guaranteed the penalty increases to 20 minutes if
there was a chance of 10% of being delayed 5 minutes and it increases to 39 minutes if there was a chance of 10% tobeing delayed 30 minutes. TCI-OR (1996) found that a guaranteed connection was worth 20 minutes of journey
time. In the present study delays and guaranteed connections are not presented directly to the respondents. In theexperiments, respondents only got information about the frequency of the connecting service. The results showedthat with a lower frequency of a connecting train, passengers experience a greater interchange resistance, because of
the possible extra waiting time in case of missing the connection (see table 1 and 2). Dependence between
punctuality, the connection time and the frequency of the connecting train is confirmed in all studies.
5. Comparison of the findings with real-world observations
We have studied three real cases in which direct services are replaced by services with an interchange and viceversa. We looked at the number of travelers between two stations, and corrected for effects of economic anddemographic growth etc. The remaining change in number of travelers is attributed to the change in Generalized
Journey Time (GJT).
We included the results of our new study in the GJT-calculation. By multiplying the different GJT-outcomesthrough the years with a journey time elasticity, a prediction of the growth caused by GJT changes can be made. The
same can be done for a GJT-calculation with the old 10 minutes interchange penalty.
The three cases are the following ones.

Bart de Keizer et al. / Transportation Research Procedia 8 (2015) 72 – 79

Schiphol – Ede-W/Arnhem/Nijmegen
The completion of the ‘Utrechtboog’ near the Amsterdam ArenA soccer stadium has resulted in a direct
service between Schiphol and Ede-W/Arnhem/Nijmegen in 2009. Before then, this trip could only be made withan interchange. The passenger growth caused by GJT-reduction on these relations is 23% (see Figure 2), whichis twice as large as expected based on the old transfer penalty. Using the results of the new study, the GJTmodel predicts a growth of 21% which is much more in line with the real-world observation.

Fig. 2: Development of the number of trips on the relation Schiphol-Ede-W/Arnhem/Nijmegen. Comparison of calculated growth when applying
new penalty (study outcome), old penalty (10 minutes) and real-world observation

Schiphol-Purmerend/Hoorn
In 2004 the ‘Hemboog’ near Amsterdam Sloterdijk was the trigger for starting up the direct service between
Schiphol and Purmerend and Hoorn. A large growth in the ridership was observed. Again, this could not be
explained by the GJT improvement using the old value of interchange (Figure 3). Application of the new values
results in a much better correspondence between the GJT model and the actual growth.

Fig. 3: Development of the number of trips on the relation Schiphol-Purmerend/Hoorn. Comparison of calculated growth when applying
new penalty (study outcome), old penalty (10 minutes) and real-world observation

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Bart de Keizer et al. / Transportation Research Procedia 8 (2015) 72 – 79

Den Haag Centraal - Arnhem
In another case (see figure 4) it has been decided to remove a direct service in favor of another connection.
In 2009 the intercity-service between Den Haag and Arnhem has been shortened to Den Haag Centraal –Utrecht Centraal. From then onwards, travelers between Den Haag and Arnhem had to change trains in
Utrecht. The drop in the number of passengers caused by a GJT-increase on this relation has been three to fourtimes higher than expected before. If the same calculation is made by using the study results a small
underestimation remains but the result is much more appropriate to the real-world observation than before.

Fig. 4: Development of the number of trips on the relation Den Haag Centraal - Arnhem. Comparison of calculated growth when applying new
penalty (study outcome), old penalty (10 minutes) and real-world observation

6. Conclusions
The outcome of this new analysis is a reference interchange penalty, that is twice as high as the old penalty. The
analysis also shows large differences in the height of the penalty depending on the characteristics of the interchange(cross-platform, frequency of trains, waiting time etc.). For the first time, this study investigates many interchange
characteristics (including their weights) together. The comparison with the real-world observations shows that the
new estimated values fit better than the old ones.
It can be concluded that in public transport studies a variable interchange penalty, that takes into account thedifferent characteristics of each interchange, is necessary to make a good forecast of travelers behavior andpassenger growth.
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