Pre-registration: Passenger Density on Stockholm Subway Platforms With and Without Blue-Light Exposure: A Quasi-experimental Observational Study
This dataset contains observational count data on passenger presence on subway platforms in the Stockholm metro system, collected as part of a quasi-experimental field study examining behavioural responses to blue LED lighting, BLED. Data were collected at four platforms across three subway stations between September 2025 and April 2026. Two platforms were equipped with blue LED luminaires and two served as non-exposed control platforms. Note: For the purpose of preregistration and documentation, the files provided at this stage contain simulated data only. These simulated files mirror the structure, variables, formats, and temporal alignment of the real data that will be analysed once data collection is complete. The core data consist of time stamped detections from the station camera system, provided as event level logs that is aggregated to minute-by-minute counts. For each platform, two zones were defined within the camera system, an exposure zone located at the platform end where trains enter the station and an adjacent reference zone with standard lighting. Automated video analytics identified human presence within these zones and recorded detections over time. The dataset does not include images, video recordings, or individual level tracking, only anonymised numerical event counts that can be summarised to passenger density measures. Lighting conditions at the exposed platforms alternated between BLED switched on and switched off, primarily in two-week periods with one four-week period, allowing within platform and between platform comparisons over time. Each camera based observation is time stamped and linked to station, platform, zone, experimental condition, and period identifiers. The dataset also includes aggregated station passage data derived from ticket gate systems at the same stations. These data describe the number of passengers entering and exiting each station at minute resolution and serve as indicators of overall station usage that can be aligned temporally with the camera data to control for variation in passenger volume unrelated to lighting conditions. To account for ambient lighting conditions, the dataset further includes environmental data from an outdoor reference station. This file contains time stamped measurements of solar irradiance and is used as a control variable for changes in natural light exposure over the study period. The data material is provided as structured tabular files corresponding to these three sources, camera detections, station passage counts, and outdoor sun exposure. The files are linked through shared timestamps and station identifiers and can be read using standard statistical software. No proprietary software is required, and the original analyses were conducted in R, although reuse is not restricted to any specific software environment.
Department of Learning, Informatics, Management and Ethics (LIME)
Blue Light on Railways for Suicide Prevention Purposes
Psychology (Excluding Applied Psychology)
That portion of the electromagnetic spectrum with wavelengths between 450 to 495 nm. Exposure to blue light at night can suppress the secretion of melatonin, disrupt sleep, and cause shifts in CIRCADIAN RHYTHM.
Specific strategies for averting suicides. These include mental HEALTH PROMOTION and monitoring PSYCHOLOGICAL WELL-BEING and other intervention programs targeting susceptible individuals.
data/BLISP_Passenger density_Hypotheses_260428.pdf
data/Platform density events - SIMULATED.csv
data/Solar irradiance at Bredäng station 250901-260427.csv