Design of a user-centered closed payment border for public transport

what: Master's thesis, DfI, TU Delft
where: TU Delft, The Netherlands
when: Sep 2015 - Sep 2016
for: NS, GVB, RET, Thales, ProRail
In the news: NOS, RTL Nieuws, Omroep West, TU Delta,, Verkeersnet, Algemeen Dagblad, Bright, TU Delft.  

Project goal
Develop user-centered solutions to improve the gate flow and user experience in the Dutch public transport system.

For this project I used qualitative research methods (e.g. observation) to do in-context user research in the public transportation systems of The Netherlands, London, Hong Kong and Tokyo. This gave insight into the usage patterns, usage issues and gave inspiration for possible solutions to these issues. I used this knowledge to propose multiple design concepts and reviewed these with the project partners. One design was further developed and user tested, before a final design was proposed.

The proposed new user-centered design of the closed payment border for public transport

Closed payment border in Rotterdam Centraal, a train station of NS

Closed payment border in Rotterdam Centraal, a train station of NS

Current system
Closed payment borders (electronic ticketing gates) are located in many (larger) train stations from the NS, and at metro stations in the bigger cities (e.g. GVB in Amsterdam and RET in Rotterdam).

These closed payment borders ensures payment by making it necessary to check-in before traveling and to check-out afterwards.

In total, these electronic ticketing gates have over a million users every day.

Electronic ticketing gates in the public transportation system in The Netherlands are designed from a technical perspective. These gates have suboptimal user experience and travellers encounter usage issues.


Research phase

Dutch system
In order to find the needs and wants of the users, I firstly conducted qualitative user research in the context of the closed payment border in train and metro stations. By using mostly observations, usage patterns were identified and usage issues came to light. Analyzing submitted complaints and conducting a minimal amount of interviews gave more insights and solidified the findings.

Example usage issue (see video): See the two gentlemen on the left side. Users sometimes validate their ticket on the validator on the left (instead of right) side of the gate, due to the limited amount of feed forward elements on the gate design that guide the users to the validator of the gate they are standing in front of. This causes usage issues and a bad user experience.


London, Hong Kong and Tokyo
Next, I went to London, Hong Kong and Tokyo to do user research in those closed payment border contexts. With the usage issues and patterns that I had found in the Dutch system, I tried to find out how the systems abroad tackle these issues.

Several elements from the closed payment borders proved to overcome the issues that users might encounter and/or improve the experience of the travellers. For instance, the overhead signage in Hong Kong (see left image, with the large crowd) guides users to a gate they can go through, even though users cannot see the gates from a distance due to the large crowd in front of it. This allows for a better throughput.



Data analysis
The insights from the research in the Dutch system was used to cluster problem areas. Insights from the research abroad was spread across these problem areas to serve as either possible solution directions for the design phase, or to strengthen the problem area that needs to be solved. 

Workshop with project partners
All insights and results from the research phase were presented to the project partners in a workshop. Cardboard gate models and a lasercut wooden gateline building set were used to let the project partners take the presented results and get a taste of building a new gate or gateline setup. 


Design PHASE

I generated partial design solutions based on the usage patterns and usage problems found during the research phase. The findings from the research abroad gave inspirations for these ideas as well.

Concept development
Four concepts, which differed in gate design, gateline setup and interaction, emerged from the ideation phase. Digital renderings and 3D-printed scale models were produced to communicate the designs. 

Concept evaluation
The concepts were evaluated with the project partners. One concept was chosen based on the criteria from the users and the concerns from the project partners. This concept was further developed into a design.


This design was evaluated with participants in a user test. Several stimuli were used: A virtual reality environment with the design placed into Den Haag Centraal station, a full size prototype with some functionality, and several (in-context) digital renderings.

Many aspects of the design were positively evaluated, with some details to be revised into the final design.


Final design
The new user-centered closed payment border proposed in this project explores the advantages of having an open gateline, in combination with many new design aspects such as the UI and feed forward aspects. This design reduces the usage issues that travellers will have at the closed payment border and improves the throughput with the placement of the doors, UI and feed forward aspects. 

The gates have a lightbox on the front, which can be turned on or off depending on whether the gate is on. The lightbox has the colour of the operator, also represented by their logo and name, which gives feed forward to the users about the operator of the gate and the direction of the gate. The green arrows and red crosses also give recognition to users about which gate can be used and which one cannot. Furthermore, overhead signage gives the same feed forward, with lightboxes and arrows/crosses, to users when they approach to the gateline. The overhead signage is especially useful when it is busy and the gates can hardly be seen. The user interface, consisting of a validator, lightstrip and display, is turned off when the (side of the) gate cannot be used. When on, the validator has a contrasting light that gives feed forward that it can be used. It gives feedback through light and sound upon validation, depending whether validation was successful or not. If successful, a light will move towards the display and a message is shown. If unsuccessful, the validator, lightstrip and display, in combination with the lights underneath the gate, will light up yellow or red, depending on the error. At this point, the doors will close.


A functional full-scale prototype of the gates was made to illustrate how it works. The movie on the left demonstrates how the gates work, when a user (1) uses a valid card, (2) uses a card with insufficient money, (3) uses a card that doesn't work, and (4) enters without tapping a card.

I developed the body of the prototype, and the Arduino coding and most of the wiring inside was done with the help of a student assistant.


A report was made for both the research phase and the design phase, to communicate the process and results with the project partners. 

Research report: Exploring user experience and efficiency of the closed payment border, 2016.

Design report: Opening the closed: Design of a user-centered closed payment border for public transport, 2016.

Both reports have separate appendices.

All reports can be viewed & downloaded here.



In september 2017, a symposium was held at the faculty of Industrial Design Engineering of the Delft University of Technology showcasing six projects in the spectrum of OV-betalen. Stakeholders from various public transport related companies and governmental institutions flocked together to experience the results of the projects and to get inspired and motivated to change the future.
In the news: NOS, RTL Nieuws, Omroep West, TU Delta,, Verkeersnet, Algemeen Dagblad, Bright, TU Delft.