Parents are being urged not to step in as lollipop staff while a council tries to fill a two-year vacancy outside a school.
The last crossing patrol person at Eynesbury Primary School in St Neots, Cambridgeshire, hung up her lollipop after more than 28 years in 2017.
Since then, parents have unofficially stepped in to help pupils negotiate a busy roundabout safely.
The county council and police have warned this could put people at risk.
More than 200 children attend the primary school, with most making the journey on foot.
Parent Susan Sangster said she often stands in to stop traffic and help children cross Montague Street and Berkley Street.
"You have a mini roundabout and a very sharp bend, so you have traffic going in three different directions at a very busy time of the morning - and they go very fast," she said.
"I do not want to see a child killed. Children are being put in danger."
The number of council-funded lollipop men and women has fallen across the UK.
However, Andy Swallowe, the council's school crossing patrol service manager, said there are currently about 50 in place across Cambridgeshire.
Eynesbury meets the threshold for a crossing patrol with more than 250 cars going past every 30 minutes.
It is hoped the position will be filled by early 2020.
Mr Swallowe added well-meaning parents would be "legally liable" if anything happens, as the role needs to be an official council appointment.
A spokeswoman for Cambridgeshire Police said parents are not "technically committing an offence" by unofficially acting as patrol staff but "could be putting children crossing the road at risk".