The car smashed into barriers in Langworth, Lincolnshire, on Thursday after failing to stop for police.
The car's driver was airlifted to hospital, with what police described as 'serious' injuries.
An 18-year-old man, and two women, aged 18 and 19, all from South Yorkshire, were arrested.
The part of South Yorkshire the teens are from has not yet been confirmed by officers.
A police spokesman said: "Police were alerted to a Vauxhall Corsa in Lincolnshire which was believed to have been stolen in a neighbouring county.
"The Corsa had failed to stop for Police when it was involved in the collision at the level crossing.
"Damage was caused to the barriers and a residential building. The collision did not involve a train."
The force said a 16-year-old boy remains in a serious condition at Queens Medical Centre in Nottingham, and a 15 year-old boy is receiving treatment at Lincoln County Hospital.
TThe incident has been referred to the Independent Police Complaints Commission (IPCC) due to the police's involvement.