12.2 Lighting linked to a movement sensor

This measure refers to technologies to influence people at risk by lighting when motion is detected in a specific perimeter. Useful for situations in which technology can be used to provide a warning to people who move into an area that they should not enter, or behave in a way that places them at risk, with the intention of influencing the person to modify their behaviour and move to a place of safety.
  • Check the laws on human integrity in your country before making the plans.
  • Check if you have a higher number of suicides during night time.
  • The sensor needs to be able to react only to persons who are in its range.
  • The effect will increase when combined with a follow-up measure as surveillance or sound warnings.
  • Lights should not be too intense in order to avoid blinding train drivers and interfering with railway signals installed on the tracks.
  • Be aware that light pollution can cause acceptance risks with neighbours and nature conservation organisations. Communicate before installing. Maybe not to be used in rural nature areas because of light pollution. Read here further details on how to reduce light pollution.
  • Impact of the spotlights for the people living in the direct environment could be an issue. For dispelling light sources there can be problems with national laws on human integrity.
  • Effective only during night time.
  • It is expected that the effects are durable.
  • Check out the controversial example of the "Bridge of life" (over the Han River) in Seoul, South Korea (https://en.wikipedia.org/wiki/Mapo_Bridge). The bridge railings were equipped with dynamic lights and positive messages which were "accompanying" the persons walking on the bridge. However, the number of people dying by suicide on this bridge rose to 93 in 2013 and 184 in 2014 when the light- & message-based suicide prevention measure was issued. Instead, in 2015 local authorities decided to replace the lights with higher railings (i.e. physical barriers) which proved more effective in reducing the number of suicide attempts. The number of people who attempted suicide on the bridge fell to 163 in 2017 and 148 in 2018 compared to 211 in 2016 when the height of the railings was increased from 1.5 metres to 2.5 metres (https://altselection.com/seoul-message-maire-plaintes/).
  • In Japan, introduction of blue LED   lights at 11 stations resulted in 84% decrease in the number of suicides between 2000-2010 compared to other 60 stations without blue light (Matsubayashi et al., 2012).
  • The installation of blue lights on platforms, even were they to have some effect in preventing railway suicides at night, would have a much smaller impact than previously estimated (Ichikawa et al., 2014)
  • Visible light of short wavelength (blue light) may cause a photochemical injury to the retina, called blue-light hazard. This blue light hazard may come from the interaction of blue light with molecules constituting the retina or accumulating in the retina with age or in pathological conditions. Studies indicating a blue light hazard within the intensity range of natural light to the retina are based on animal experiments. The relevance of these experimental data for human pathological conditions is not very clear. In general, the probability that artificial lighting for visibility purposes induces any acute pathologic conditions is low (Kadotani et al., 2014).
  • Blue lights have been implemented in Belgium (in one station for the moment: Dave-Saint-Martin near Namur) and 3 other stations are going to follow at the end of 2014. INFRABEL   will evaluate the results of this measure in these pilot areas.
  • Other literature suggests that once a person has crossed the “decision-line”, it will require much more than a barrier or a blue light to stop them (Bhui et al. 2013).

last update: 2023-03-01 Print