The school board of Affeltrangen decided on the measure after a 15-year-old girl pedalling on her bike was run over by a van last month.
The incident occurred on October 21st after the 59-year-old van driver overtook a tractor.
Despite attempts by a Rega emergency resecue team to revive the girl, she died at the scene of the accident.
“This tragic accident has moved us to action,” Roger Hollenstein, president of the Affelttrangen secondary school told the local Thurgauer Zeitung daily.
As of Monday wearing a reflective vest is compulsory for all students cycling to school in the rural region, in addition to the wearing of helmets.
Hollenstein noted that during his time with the school three students had died travelling to or from the school, with many students cycling to classes from villages in the outlying area.
Earlier, students were advised to wear reflective clothing but many appeared to have ignored the recommendation, the Thurgauer Zeitung said.
School authorities consulted with the canton before bringing in the new requirement for the winter season.
Bei RoadCross Schweiz, an organization that campaigns for road safety, praised the measure, with a spokesman saying he did not feel it was “disproportionate”.
School headmaster Hansmartin Keller said officials would be conducting checks over the next few days and weeks to ensure students are complying with the new order, the Thurgauer Zeitung reported.
It will take some time for children to be become accustomed to wearing the vest “but at some point they will take wearing them for granted”, Keller is quoted as saying.