# How Long Does It Take to Stop? Are Children Able to Stop on Demand?
## 1 Introduction  
As children reach school age, they become more independent and active road users. Despite this, they remain the most vulnerable group of road users as pedestrians [1]. It is common for children to travel by foot to various destinations, including school, friends' houses, and sports activities [2]. The American Academy of Pediatrics recommends that children under the age of ten should not be unsupervised pedestrians in road traffic, except under special conditions [3]. However, it may not always be feasible to practice and supervise all trips. It is strongly recommended that children practice walking to school with adult supervision before being allowed to walk alone [4]. According to [PERSON] [5],children up to the age of approximately eight years are unpredictable and untrustworthy as pedestrians in road traffic due to their psychological development. Even older children, aged 8-9 years, are still easily distracted. It is crucial for children to focus their attention on the hazardous situation and avoid distractions from other things [4; 6; 7; 8]. Children crossing the road tend to focus on their immediate surroundings, often neglecting traffic [6; 9]. It is vital to educate children on the significance of paying attention to traffic when crossing the road. Their attention is often drawn to non-traffic related objects such as animals or other children [4; 8]. Thus, inadequate observation of traffic and failure to stop before crossing the road are major contributing factors to accidents, as highlighted by [PERSON] et al. and [PERSON] et al. [6; 10; 11]. Accurately estimating the speed and distance of an approaching vehicle is crucial to avoid critical situations. It is important to note that speed estimation is a complex task that requires considering distance [12]. According to various studies, children's ability to estimate distances ranges from approximately six [13] to approximately nine years [14] (as cited in Uhr [12]). Furthermore, studies have demonstrated that children between the ages of 10 and 12 possess the capacity to estimate the velocity of approaching vehicles [14] (as cited in Uhr [12]). It is worth noting that 10-year-old children tend to use distance rather than speed as a reference for their judgment [15]. Furthermore, [PERSON] et al. [8] identified a correlation between the time taken to clear the roadway and the speed of the next approaching vehicle. The study indicates that younger children have a shorter escape time compared with older children. Each age group (7-8 years, 9-10 years, 11-13 years, and adults) exhibited a significant difference to the next age group. Notably, the age group of 11-13-year-olds exhibited no statistically significant variation in their results when compared with adults. The remaining escape time averaged at 0.7 s for 7-8 year olds, 2.7 s for the 9-10 year olds, and 4.9 s for the 11-13 year olds. Younger children were able to cross the road safely in significantly less time than adults, who exhibited an escape time of 5.7 s. These findings suggest that younger children perceive a shorter distance between two vehicles as safe compared with adults or older children. However, in some situations, it may still be more appropriate for all pedestrians to stop and wait for traffic to pass or for vehicles to stop. It has been demonstrated that children aged six to seven encounter difficulties in interrupting a movement once it has been initiated. This has significant implications for their ability to respond promptly in dangerous situations [16] (cited in [PERSON] et al. [17]). This task requires a high level of alertness, which refers to the ability to quickly establish a general readiness to react [18]. It is important to note that alertness increases significantly between the ages of 5 and 11 years [19] (cited in [PERSON] [12]). However, for younger children (6-8 years), there are significant inter-individual differences. The attainment of an average adult level of alertness is customarily observed at approximately 14 years of age.