A key problem is the 20 second ticket validation window, where any failure results in a 3 minute blockade, preventing further ticket purchases or additional validation attempts. This short time frame and lack of information about these limitations are highly controversial, as they fail to accommodate various user scenarios. Consequently, this solution does not meet the accessibility requirements of WCAG 2.2.1 (Timing Adjustable). Research suggests that these feature is not created by app developers, but is result of transport operators guidelines aimed to prevent “free-riding”. With this in mind, I treat my case study as a suggestion to take both interests into account, minimizing interference with the app’s structure, but to allow users to avoid making an unnecessary mistakes.
With the European Accessibility Act becoming law in June 2025, mobile apps ticket validation accessibility should definitely start being consulted. Digital accessibility, including WCAG standards, will be not only guidelines, but a legal requirements.
My tasks were to:
This is a conceptual, non-commercial project.
My research indicates that the specified time to activate a ticket aims to deter 'free-riding,' where some passengers validate tickets only when a ticket inspector appears in the vehicle. While this assumption seems reasonable, it does not consider groups who want to buy tickets through a mobile app but may face difficulties:
Developers should account for these scenarios and provide at least one additional validation attempt—as these users have already paid and are trying to comply with public transport regulations. The following quote shows that there are more such people using mobile tickets than buying physical tickets - and it is increasing year by year.
"For the first time, ticket sales on mobile apps overtook traditional methods. Passengers bought more than 40 million tickets on apps, a 43 percent increase from the previous year in 2022."
Warsaw residents choose mobile payments (ZTM Warsaw - report 2023)
It turns out that this is a common frustration of people who are using mobile tickets. Online forums questions, social media posts, reports in the customer service section, as well as online articles on popular media portals are being written on this topic. Sources presented below are mainly related to Warsaw, but considering that the zBiletem application allows purchasing for more than 60 cities in Poland, this problem can frustrate a broader group.
Why is it also important from an app developer's business perspective? Users who make a payment for ticket and then face a problem with ticket validation will become frustrated and there is a high risk that they will use a competing app or another form of purchase.
To improve ticket activation process, in my redesigned version of the app, users will have an option to request additional time for ticket validation—allowing them a second chance in case of any difficulties. To improve process clarity, the "My Tickets" screen should display a message explaining the 20-second validation rule and the option to request extended access.
My final suggestion enhances the system's ergonomics and provides more flexibility in ticket activation, aligning with accessibility and Nielsen's Heuristics:
Obviously, suggested feature should not work over and over again - in order to determine an appropriate solution for stakeholders, there should be consultations on this issue. There is a lot of options, such as additional activation attempt once an hour or next attempt for one specific purchased ticket. It is a try to find a consensus between different interests. From my perspective before any decisions, the best solution would be to conduct additional research with users at first, especially in the group that may encounter difficulties. Then also to take into consideration interests of the city as a beneficiary of ticket purchases, in order to effectively eliminate the risk of free-riding.
