Measuring crowding on a historic street in Valencia

The question

How can the carrying capacity of a historic street be estimated, and how can image sensors be used to monitor in real time when and why it is exceeded, so that preventive management measures can be triggered?

The method

Experimental case (design science research) on a pedestrian street next to Valencia cathedral: a 2D camera with automatic people counting (convolutional neural networks), readings every 10 seconds between 9 am and 7 pm; usable area calculated with GIS and a 3D model; comfort thresholds based on proxemic distances; analysis of three representative days (23/11/2023, 5/3/2024, 12/5/2024) cross-checked against the events calendar.

What the study finds

≈ 58 m²of usable area in the camera's viewOnce obstacles and clearance strips along the walls are removed, the area actually available to visitors in the camera's field of view measures about 58 m² (57.60 m²); thresholds are computed on this surface.

216 peoplecritical threshold in the monitored areaThresholds rest on interpersonal distances: 36 people in the area at once (1.2-2 m apart) is rated very acceptable, 74 (0.8-1.2 m) acceptable, while 216 people (under 0.8 m) signals a critical situation.

38,436 peoplepedestrians counted on the typical dayOn the typical day chosen (23 November 2023, with a weekly traditional event) the camera counted 38,436 pedestrians; thresholds were exceeded at the end of the weekly event and at the start of free cathedral visits.

54,696 passagesrecorded during the FallasDuring the Fallas (5 March 2024) recorded passages rise to 54,696; a threshold is crossed with 60 pedestrians right after the midday fireworks display in a nearby square.

On the city's main religious festival day (12 May 2024) 147,058 people were counted, and the comfort level was exceeded from the moment monitoring began. Across the three days analysed, threshold breaches coincide with local calendar events.
Citing other studies, the authors report that 2D cameras can reach up to 98% counting reliability and work well in small-scale public spaces; the study does not present its own validation of the counts.

From the study's figures

The study area: Miguelete Street, next to the cathedral, in Valencia's historic centre.
Figure from Viñals, M. J.; Orozco Carpio, P. R.; Teruel, P. et al. (2024), CC BY 4.0 licence.

Why it matters for ports and cities

For historic cities with concentrated inflows, potentially including cruise visitors (whom the study does not address directly), the paper proposes a method to turn a street's carrying capacity into operational thresholds and real-time alerts. In the case analysed, threshold breaches coincide with local calendar events, useful information for scheduling group arrivals.

Limitations

A single street and three illustrative days; generic proxemic thresholds that do not account for differences between visitors; no distinction between residents, tourists or cruise passengers; informal events not tracked and possible data loss.

Full reference and source

Viñals, M. J., Orozco Carpio, P. R., Teruel, P., Gandía-Romero, J. M. (2024). Real-Time Monitoring of Visitor Carrying Capacity in Crowded Historic Streets Through Digital Technologies. Urban Science 2024, 8, 190 (MDPI).

Read the original study ↗

Summary written by the ODYBOAT Observatory in our own words. Tables and figures belong to the authors.