The signs they are a-changin’

Published March 30, 2018 in Blog

Progressive transport authorities understand that their passengers are expecting more. More real-time information on their services, more delay information, more information on connecting services and more map-based assistance. Delivering this information on the street is a constant challenge, particularly with the growing support for environmentally-sustainable solutions and ever tighter budgets.

New display technologies have the potential to break the shackles of history and deliver where no technology has delivered before.

Electronic displays have been used for the past 25 years to show bus and train arrival times. Transport authorities were early adopters of LED and LCD technology, but these were not without their problems. Multiple-line LED displays showed arrival times with perhaps one scrolling line of special information. This technology remains particularly well-suited to outdoor displays servicing a large number of people. However, it is non-graphical, not suitable for small groups and power hungry.

LCD displays look a lot more modern and have the flexibility of a graphical display. Unfortunately, this technology is difficult to see under direct sunlight. Turning up the brightness partially helps but uses more power and reduces the longevity of the signs. Add-on technologies such as optical bonding improve the visibility but add significantly to the costs.

Even a mobile phone app, which is very cost-effective and is an excellent solution for many situations, is not a panacea at busy bus interchanges, railway platforms and major stops. Many customers still want a visual display at the stop so that they can keep using their phones for other tasks.

With tighter budgets, many transport authorities prioritise their spending by providing relatively expensive displays only at major bus stops and train stations, with printouts of route schedules at suburban stops. In some cities, a lower cost display is used at premium stops. Auckland and Melbourne are some Australasian examples of this smaller, more personal sign approach. However, most of these displays (large or small) need to be connected to the electrical distribution network and the cost of this adds significantly to the total capital cost.

It was to address these issues that Trapeze delivered its latest generation of passenger displays, based on electronic ink (e-Ink). This is the technology that underpins the Kindle reader and one that is now hitting its strides in a range of signage situations from retail to road signs.

e-Ink differs from other displays in two very important ways: it is both bistable and reflective.

Bistable means that each pixel in the display will adopt one of two states (black or white) and will stay in that state until changed. Unlike an LED that emits a light when turned on and then shows nothing once power is removed, an e-Ink pixel will show its last state until that is changed. Power is used to change the state but no power is used to maintain the display. This means that a panel made of e-Ink pixels will show the same image forever, even if it is subsequently disconnected from electricity.

Reflective means that it needs an external light source shining on the display for it to be seen. LCD displays also need a light source but the light is behind the display; because the LCD panel is essentially like a set of Polaroid sunglasses, a brighter light is needed for the display to be seen. In an outdoor environment, the filtered light then has to compete with the sun just to be seen.

In addition to avoiding light pollution, the reflective features of e-Ink displays makes them easier on the eyes, provides a wider viewing angle than most other displays and makes the content displayed perfectly visible in all light conditions, from the glow of a nearby streetlamp to direct sunlight. Pretty much perfect for modern displays showing information to passengers at a bus or tram stop.

Combining e-Ink technology, batteries, a small solar panel and a 3G SIRI interface means that the next generation of passenger information signs opens a whole new range of opportunities to transport authorities.

The very low power consumption finally means that large screen display is possible without needing a mains electricity connection. As the provision of power can often cost $5,000-$10,000 per site, not having to provision for this is on its own a huge saving. Not having ongoing (and ever rising) costs also adds value to the e-Ink solar solution. This allows public transport providers to extend their commuter information to far more stops and to deliver significantly greater value to riders.

As a fully graphical display, e-Ink displays also bring the opportunity to deliver enhanced messages. In addition to showing arrival times, it is also now possible to show a map of the route or a detailed set of directions. A complete timetable (just like the printed timetable) is no problem and can be shown during off-peak hours or at locations where there are infrequent services.

Connecting to the signs has changed also. For many years, the signs’ interfaces were proprietary to real-time passenger information (RTPI) vendors. This made a lot of sense at the time as it allowed public transport authorities to specify whatever functionality they wanted without having to worry about the details of integrating various systems. However, it left them locked in on a major cost component of their RTPI system.

Fortunately, more and more vendors (Trapeze being one of the first) began supplying open CEN SIRI standard feeds of data as well as their own sign protocols to remove this barrier. The SIRI interface means that these signs will work “out of the box” and can be simply located at any stop in the transport network. No interfaces need to be developed as the signs will use your existing SIRI stop monitoring service data feed.

Delivering real-time information to passengers is now possible at significantly lower cost with the additional benefits of being ‘green’. Fully graphical e-Ink displays capable of showing key information that lasts forever are changing the very concept of signage, and the winner is the passenger.

With apologies to Bob Dylan – the signs they are a-changin’, and it is great to see.

SIRI data feeds are available in all Trapeze RTPI intelligent transit solutions and allows transport authorities to introduce some competitive tension in their sign tendering process by opening up their passenger information signs to a range of third-party solutions. By bringing e-Ink technology to the market, Trapeze continues a long history of innovation.

Mode of Transport

Bus, Trams/Light Rail, Ferry


Intelligent Transport Systems

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