Citation: Renard, A.; Novaˇ cko, L.;
Babojeli´ c, K.; Kožul, N. Analysis of
Child Traffic Safety near Primary
School Areas Using UAV Technology.
Sustainability 2022, 14, 1144. https://
doi.org/10.3390/su14031144
Academic Editors: Aleksandra
Deluka-Tibljaš, Irena Ištoka Otkovi´ c
and Sanja Šurdonja
Received: 10 December 2021
Accepted: 17 January 2022
Published: 20 January 2022
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sustainability
Article
Analysis of Child Traffic Safety near Primary School Areas
Using UAV Technology
Anton Renard
1
, Luka Novaˇ cko
2,
* , Karlo Babojeli´ c
2
and Nikola Kožul
3
1
School of Transportation Sciences, University of Hasselt, 3500 Hasselt, Belgium; renardanton@gmail.com
2
Faculty of Transport and Traffic Sciences, University of Zagreb, HR-10000 Zagreb, Croatia;
karlo.babojelic@fpz.unizg.hr
3
Ernst und Young Ltd., Guangzhou 510623, China; nikola.kozul29@gmail.com
* Correspondence: luka.novacko@fpz.unizg.hr
Abstract: Road safety in primary school areas is a delicate issue due to the vulnerability of children
as road users. They are inexperienced traffic participants and sometimes their behavior in traffic
situations is unpredictable. This paper reports a safety analysis conducted using video processing
of conflict trajectories of vehicles and active transportation users (AT users). The videos were
collected using unmanned aerial vehicles (UAVs) as this technology does not affect the actual
behavior of traffic participants. Due to their airborne position, UAVs can conveniently gather
information about driving behaviors and the exact positions of various participants. The safety
analysis was conducted using surrogate indicators suitable for evaluating the risk of potential
collisions as they incorporate both spatial proximity and speed. Three conflict indicators were used
in the safety analysis: (i) time-to-collision, (ii) post-encroachment time, and (iii) heavy braking.
The methodology was tested in a primary school area in the city of Zagreb. With the applied
methodology, a total of 43 potential conflicts were identified in the school area (14 time-to-collision,
23 post-encroachment time, and 6 heavy braking). Based on the determined potential conflicts,
safety measures were proposed to decrease the number and severity of potential conflicts and to
increase traffic safety near school areas.
Keywords: child traffic safety; school areas; unmanned aerial vehicles; surrogate safety indicators;
road traffic safety analysis
1. Introduction
This paper focuses on one of the busiest mixed-traffic environments: school areas.
The main reason for this focus is the vulnerability of the traffic users in these areas, who
are young children participating in mixed traffic. The main aim of the present paper
was to develop a new methodology for the analysis of child safety in school zones using
unmanned aerial vehicles (UAV) and image detection technology. Child traffic safety was
evaluated using surrogate safety indicators extracted from drone footage. The practical
contribution of this work is reflected in the ability of local communities to analyze traffic
safety near schools, identify priorities, and implement measures to increase traffic safety.
School children are recognized as one of the groups most at risk of involvement in
traffic accidents resulting in death or serious injury [1]. In the developed world, pedestrian
accidents remainone of the greatest causes of injury, disability, and death [2]. In 2018, the
European Transport Safety Council (ETSC) published a report on child deaths on European
roads, showing that one-third of all children killed on European roads were pedestrians [3].
For older child pedestrians, the majority of crashes occur during the daily commute to or
from school and leisure activities [4].
The road safety of school areas is a very topical but sensitive issue. The reasons for
this are twofold: school areas contain many vulnerable youngsters and experience chaotic
Sustainability 2022, 14, 1144. https://doi.org/10.3390/su14031144 https://www.mdpi.com/journal/sustainability