Rail & Public Transport

LED railway light signals

LED’s are electronic light sources with several technical advantages. Railway light signals equipped with LED’s will replace the conventional candescent signals with light bulbs in the near future.

Approach

By order of Prorail (the Dutch railway network manager) and a well known Dutch manufacturer of railway signals, Intergo took care of the ergonomic design of the perception aspects of these signals. We started with a risk inventory and desk research. Signal brightness and signal identification came out as of first importance. A series of iterative visibility studies with train drivers led to an acceptable brightness.  In a simulation we studied effects of the wider beam of light of LED signals. Results indicated that in complex track layouts, drivers made more signal reading errors with LED signals than with candescent signals. In a mixed situation of candescent and LED signals, longer reaction times were observed. Now a new simulation is being developed, serving as a tool for early assessment of a proposed signal positioning.

Download

We presented a paper about the ergonomic implication of replacing traditional candescent light bulbs by LEDs in head lamps and railway signals during the Third International Conference on Rail Human Factors (March 2009, Lille). You may download this paper.