Table of contents
Displays in public transportation perform a number of functions. Smaller sized models are present in the vehicles themselves, such as in the cash registers. Large-format variants are visible at most stations or stations. All of them are used to inform passengers about, for example, route details, current weather conditions or, most significantly, departure and arrival times and possible schedule changes.
Screens used at key points in transportation infrastructure have a specific role. They are the gray eminence in urban space – they have a significant impact on passengers’ daily decisions, yet they are so firmly entrenched in their consciousness that they go almost unnoticed. Provided they work properly and are properly sized for where they are installed.
Standards and requirements
The requirements for displays used in the transportation industry differ from those for other applications. Depending on the final location of a given LCD module – the interior of a bus, a space belonging to a streetcar stop, or a train station – it is certain that it will have to meet a number of additional requirements, usually officially defined. In the case of displays installed in trains, for example, the PN-EN 50155:2018-01 standard specifies the temperature range of the devices, as well as their resistance to vibration and the permissible intensity of emitted electromagnetic interference, which can affect the operation of the rest of the apparatus in the vehicle.
Any shape
Readability of information is crucial for people using public transportation. The mounting space accommodating LCD modules is often not only limited in size, but also does not conform to standard display aspect ratios and dimensions – there is no guarantee that typical solutions will be the optimal solution for such applications. Thanks to developments in TFT glass cutting technology, manufacturers can now achieve displays in the shape of a circle, square or an extremely stretched rectangle of unusual dimensions. Such LCD modules are rarely used to display only advertising content, but are ideal for showing, for example, the route of subways, trains or buses.
Key parameters
Displays chosen for transportation application projects must not restrict passengers’ access to information – so it is worth paying attention to full viewing angles (89°/89°/89°/89°), adequate screen brightness (at least 700 cd/m2, optimally between 1,000 cd/m2 and 2,500 cd/m2), backlight uniformity and high contrast. All these factors guarantee good readability of the presented content even in bright sunlight.
However, the parameters responsible for readability will be of no use when the LCD module… does not work properly. It would be hard to imagine a railroad station where screens with the exact times of departures, arrivals and possible delays of individual trains would be turned off for an hour or two during the day. The need to operate 24 hours a day, seven days a week means that displays used in transportation have a mean time between failures (MTBF) estimated at at least 70,000 hours of operation. Thanks to such a solution, they are perfect for applications requiring all-day operation, and thanks to their optimized backlight system, they have lower electromagnetic disturbance levels and lower power consumption. Unisystem also offers models capable of up to 100,000 hours of trouble-free operation, which in practice means operating the device for more than 10 years at full LED output without interruption.
A popular display for this type of application, for example, is the 46-inch P460HVN05.0 from AUO. This is the standard size used at information kiosks or travel or passenger service points. Several solutions from Litemax – such as the SSF3700-Y, with a brightness of 2,500 cd/m2, or the SSH3805-I with increased LED life – will also work well for public transportation. All are available from Unisystem.
E-paper – another solution
An alternative to LCD modules used as timetables or information boards can be the use of e-paper displays, which, thanks to their properties – excellent legibility in full sunlight, full viewing angles, and energy efficiency (low power consumption following only when changing the information displayed) – provide excellent readability of the content presented on them. The only condition for the proper functioning of such a solution around the clock is to provide it with additional illumination at night.
Screens at cash registers
Another group of devices closely related to transportation and actively using LCD displays are cash dispensers. This type of application uses a variety of technologies for displaying information, and their choice is usually keyed by the size of the screen itself. For devices requiring several-inch solutions, the economical 7-inch displays from Winstar are worth recommending. For the small, more classic cash register formats that, for example, are often seen inside vehicles, 16- or 20-character and 2- or 4-verse LCM displays with 12:00 a.m. viewing direction, also made by Winstar, can be used.
Effective communication
While the vision of a world without ubiquitous displays may seem soothing and in tune with nature, it is worth looking at the reality around us with a sober eye. Without skillfully implemented screens at key points in the transportation infrastructure, and thus without appropriate media to convey important information, passengers’ lives would become more difficult. Even the smallest change in train and bus schedules would not be effectively communicated without the solutions seen at key points in public transportation systems today. Contact us for support in implementing your project.
