Travelling Hiccups 4

After 8 days of smooth travelling, we assumed Calder has learned how to travel to and from work, so we stopped monitoring his journey. Imagine our surprise when we found he's still at Buangkok mrt two hours after his Dad departed from him there. It was nearing 1.30pm, and we got concerned because he would usually have sent Mommy his selfie by this time. WhatsApp live location (we have started sharing his location this way with his job coaches, in case he arrives late) showed he was at Buangkok when he should be at Siglap. Daddy went to look for him and put him on the train. Thank God he managed to follow the routine of changing train at Outram, and alighting at Siglap. 

In the evening, I watched the footage of his visual tracker to ascertain the cause of this hiccup. Oh, it's because trains at both platforms arrived at the same time. Since Calder was small, I've noticed his reluctance to board a train when the train opposite has not moved off. He would wait for buses to move off too, before walking away. In the footage, the trains kept arriving simultaneously. His video would show him looking at the side he's supposed to board, then turning to see the train arriving or leaving at the opposite platform. He would continue to watch the opposite side until its train had fully left. By this time, his side of the train would also have left, or be blinking the warning that the train door was about to close. I stopped counting at the 13th pair of trains. In this way, Calder got stuck for 2 hours waiting for a train that never arrived alone. Thank God he was able to leave his "post" when prompted by the Dad. But I don't know how to prevent such a hiccup from happening again, short of herding him into the train. (He's already been trained to leave from home. When he was discovered playing at the HDB lifts, I took to sending him to the bus stop. Would I now need to send him to the mrt station?)