Secure Cashless Payment System for the Dutch Public Transport

To make their public transportation system more secure for drivers and passengers, as well as to reduce delays and dwell times at bus stops, the Dutch government had passed a law obligating all public transportation companies in the Netherlands to transfer to a cash-free payment system by the end of 2017. A secure and scalable solution for cashless payments was needed to satisfy the new demand across the Netherlands.


When two of our HTEC teams started working on cashless payment solutions, they encountered challenges that do not necessarily occur often. The main challenge our teams faced was how to make the payment system as customizable and open as possible, keeping in mind the evolving needs of different future clients.

As with any product that contains many different integrated parts, there were issues with the pieces of hardware. Card readers, for example, had the wrong specifications and their performance was below our expectations. After a substantial back and forth with the manufacturer, they finally agreed to send amplifiers for improved performance and our teams managed to install them swiftly before the launch of the new system across the Netherlands.

Working closely with the Telexis team, we had the opportunity to see how the buses were put together and our teams were there in person to install the devices and connect them with the software.

Working on the software solution, we had to create a stable system that could be used by a large number of vehicles, which brought its own set of challenges. In order to propagate system updates and fix bugs on a large scale, avoiding manual updates on every vehicle, Auto Updater service was installed. The challenge was the integration with the transaction management part, which is a separate system.

Overall, working on this project strengthened our resilience to the unexpected, making us ready to take on and successfully deliver any technically and operationally complex solutions.


HTEC Group has extensive expertise in building technology for transportation and logistics. Cooperating with Telexis, we created several systems for cashless ticket purchasing and other adjunct operations.

From the very beginning, we were involved in the selection of Telexis Sales Unit (TSU), the integration of all hardware (touch screen & computer, printers, card readers, Payplaza PIN terminals, modem, antenna, etc.) and software solutions.

Solution 1

TSU (Telexis Sales Unit) is a device that enables users to buy tickets and other products with OV-chip cards that are universal means of payment for public transport in the Netherlands. The unit is designed as a self-service box with a Windows 10 Panel PC, built specifically for this purpose. We needed to enable printing and third-party credit and debit card management.

The unit has two basic functionalities and both of them have passed certification procedures. First, the selection, purchasing, and issuing of one-time paper ticket. Second, delivering previously bought products on OV-chip cards. Customers can collect them by placing the OV-card on the TSU. For this Windows platform, we have chosen .NET 4.5, C#, WPF.

The unit consists of four components:

  • Core service — in charge of all business logic and libraries such as communication with Payplaza and the printer.
  • UI app.
  • AutoUpdater service — automatically downloads a new version of the software and installs it, has a rollback option, so it’s error-proof.
  • Monitoring service — collects all ata about the system and sends it to the external monitoring tool/dashboard.

These components communicate with each other via WCF, which makes it extremely easy to implement a new UI across the board using the existing functions. All other libraries are switched on using dependency injection which enables us to quickly implement the same interface for a different client. For example, we can use the existing printer interface on a new printer by injecting a different library for that type of printer to make it work.

Solution 2

Arriva OBSU (On-Board Sales Unit) allows credit and debit card payments. Our solution enables the coordination between two existing systems:

  • MBC (Master Board Computer), which acquires location data, and
  • Quarto Kassa, which handles payments and ticket printing.

Because these systems couldn’t communicate, bus drivers had to login two times at the beginning of their shift. Moreover, the Quarto Kassa printed tickets did not include information about the bus line and stop prior to the integration of the two systems.

Finally, we implemented a Monitoring Service which allows transportation companies to track transactions and analyze customer behavior. OBSU collects a large amount of data (the number of transactions, number of tickets sold on certain lines or bus stops, etc.) and forwards it to the back-office. The component is extremely useful as it also monitors system malfunctions and failures, and it alerts administrators who can then quickly address the issue.

Segmentation of the system, which we paid significant attention to, makes it possible to propagate changes to one part of the system without affecting the others.


The systems we developed have several advantages compared to other forms of ticket purchase. First of all, passenger and driver security is met by providing them with an easy touchless and cashless ticket purchasing solution. TSU also allows them to collect their previously bought OV-chipkaart products.

The devices are self-servicing and robust, which significantly reduces their maintenance costs. Detailed and more efficient reporting is available in the system, which in turn provides better insight into customer behavior and market demands.

Using the systems we created, passengers are now able to buy tickets cashlessly, the accounting time is reduced, and the maintenance costs are lower. In addition, paper and coin production costs will decrease in the long run.