Less other train accidents on level crossing
The problem: a second train behind the first train at a level crossing. The solution: hide technology, hide the real situation and lie.
Traffic Engineering & Control, March 2011.
Last update Oktober 2017.
Dr. Leonard Verhoef,
applied cognitive psychologist.
For designing complex things.
Not a designer.
After studying educational psychology and applied experimental psychology Dr. Leonard Verhoef did research on human thinking. He applied scientific cognitive psychological knowledge in designs for car drivers, skippers, and high speed train drivers. His designs for public transport passengers and people trying to escape a disaster, reduce reading time, travel time and the number of casualties substantially. This also applies for controlers (train, traffic, process) in normal practice, disturbed situations and when disaster strikes.
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The first solution is giving trains priority and sue the tracks crosser in case of an accident. To have a strong case the law can be put on a sign near the tracks (see figure 1 at the right).
Figure 1. A legal message|
Tram has priority.
Source: Tram station. Brussels Midi, Belgium, 2010.
Explain technology in static text
|The second solution is to communicate technology that causes the danger, e.g. present the number of tracks (See Figure 2).||It is not sure that from knowing the number of tracks, the tracks crosser will conclude that there might be another train coming on one of the other tracks.||
Figure 2. Message describing the technical situation |
Source: common practice in the US.
|It might be better to present the consequence of the technology used: another train might appear (see Figure 3).||The main advantage of these static text solutions still is a legal one. In court the track company can blame the track crossers saying: Don’t blame us, we installed a sign. The main disadvantage of static text solutions is a psychological one. Static text is unconspicious and people do not read them. Especially track crossers that need them most: regular users.||
Figure 3. The danger in the message|
WAIT, until the red light is switched off, another train might appear.
Source: common practice in the Netherlands.
Piece of art
|Belgium Railways and Netherlands railways have a third solution for the problem. They asked artists to solve the problem (see figure 4 at the right). This piece of art might be interpreted as piece of art and not as a warning.||This is called function fixedness: the obvious function is detected first and a second function is not detected. Functional fixedness is commonly used in riddles.||
Figure 4. An artistic message|
Do you want to stay alive? Just wait for a moment.
Source: The Netherlands, experimental sign ProRail. http://www.nicospilt.com/index2.html
Static graphic solutions
A fourth solution is using graphics. Graphics can be more conspicuous than text because a complex situation can be perceived in a glance (compare Figure 3 and Figure 4).|
Designing comprehensible graphics is difficult as Figure 5 shows. The arrows in Figure 5 can be interpreted in the following ways.
|It is unlikely that hurried track crossers focusing on the first train and seeing this sign (figure 5) in the split second available will be capable of making the cognitive psychological analysis above, select the correct interpretation and finally will conclude: I don’t cross.||
Figure 5. A message with arrows
Source: sign used in Austria.
Dynamic text solutions
|The solution discussed so far are static and as such inappropriate to attract attention. The only way to catch the attention of the inexperienced and experienced track crossers is the fifth solution using dynamics as in figure 6 and 7.||The dynamics are used in other train situations only, on top of the one train only coming signs. In this way experienced track crossers will distinguish between one and two train situations. Figure 7 is to be preferred because it directs attention immediately to the text.||
Figure 6. Conspicuous light with text explaining the technical situation
Figure 7. Conspicuous text explaining the technical situation
A dynamic realistic solution
The disadvantage of a text solution is that the text is not read, especially not by the focus group: track crossers having experience with that track. Parker (2002) investigated a sixth solution: a realistic dynamic presentation including moving trains, blinking arrows and left-right looking track crossers heads (see Figure 9). 27% of the track crossers interpreted the sign as a general always look left and right sign for one or more trains, 41% interpreted the sign as do not cross, a train is coming and 20% did not understand the sign at all. In a follow-up survey four percent directly related the sign to the presence of two trains.
|The design strategy is as in Figure 2: present technical reality and hope that the tracks crosser will understand the danger.||Figure 9. Dynamic realistic graphics for the hidden train problem|
Source: Parker 2002
A dynamic psychological solution:|
The sign in figure 9 is most conspicuous (a large area lightening up) when the track crosser physically can’t cross, i.e. when there is a train on the level crossing. The message should be most conspicuous when the tracks crosser decides to cross. This is the time period when there is no train on the level crossing yet, i.e. when the tracks crosser can cross but should not. In the seventh solution the sign should graph the crosser by the collar just before the moment he decides to cross. The best, of course would be some kind of subject too close to the tracks detection that switches on in the period the decision is made only. Next best is an estimate of that moment.
|The sign in figure 9 seems to be for a second train from the opposite direction only. In that case the tracks crosser can see both trains. The message to communicate is much more complex when the second train is hidden. A first crossing train can hide a second train from the opposite direction after crossing. A slow train on the first track to cross can, before crossing, hide a fast second train that will arrive at the crossing first.||In those situations the solutions discussed so far, might encourage the track crosser to cross because they support the strategy: OK, another one is coming, I don’t see it yet (approaching from the other direction as usual or according to some signs), I still can make it. In practice the track crosser might cross the first visible train just in time but then is caught by the hidden train. Designing a sign saying: two visible opposite trains crossing simultaneously proved to be difficult. How to communicate the more complex situation of a hidden second train? Presenting the real situation is a dead end. Communication should not be an explanation of the technical situation nor a presentation of reality.||The best solution is message saying somehow: This is a more complex and dangerous situation than usual. Just don’t cross. This graphic does not need to match reality but should be understood instantly.|
Heavisides, J.,Barrett, M. & Hesketh S. , (2009). Another train coming warnings at automatic level crossings Third International Conference on Rail Human Factors, 3rd to 5th March, Lille, France.|
Parker, S.A. , (2002). Second Train Coming Warning Sign Demonstration Projects Research Results Digest. no 51.
|More applied psychology for public and transport information|
|More applied psychology for other domains:||
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Leonard Verhoef, theoretical and practical background. From an experimental coginitive psychologist to a designer of simple and complex daily life systems in a technical future.
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