Hayden was instantly given help on the spot of the accident, and later transferred to the nearby hospital where he is still in critical condition and fighting for his life.
Hayden was taken to the hospital after being struck by a auto while training on his bicycle along Italy's Adriatic coast, following a weekend Superbike race at the Imola circuit.
Hayden now has his fiancé Jackie by his side as well as his brother Tommy and mother Rose, according to a report on Fox Sports MotoGP.
A morning bulletin from the Bufalini Hospital in Cesena where Hayden has been taken confirmed he remained in intensive care and that there had been no change in his condition.
Polytrauma is a medical term which means that a person has suffered multiple traumas to the body. He was transported to a local hospital before being moved to Cesena.
Hayden began racing in the World Superbike Championship in 2016.
How is Nicky Hayden now?
Flags fly at half-staff in state for Peace Officers Memorial Day
The first recorded was officer Newton Perkins of the Jackson Police Department, who died in July 1876. The president made respect for law enforcement a theme of his remarks outside the U.S.
"Nicky is one of the best friends I've ever had in the paddock", wrote the seven-time MotoGP champion on Instagram.
"After a few years, we fought for the title down to the last race in Valencia and, unfortunately for me, he won and became MotoGP world champion".
"We were teammates in his rookie year in 2003, when he was a young guy making his debut in his first European experience". After the race we shook hands and hugged.
He rode for Repsol Honda, Ducati Corse, Drive M7 Aspar Team, and Estrella Galicia 0,0 Marc VDS.
"With a bit more time you start to understand, it's a great shame because Nicky was a great rider", he added.
The dangers of training on public roads have been highlighted in recent weeks by other accidents affecting professional athletes.
From the past season, he returned to the Superbike Championship with the Red Bull World Superbike Honda, replacing Sylvain Guintoli alongside Michel van der Mark.
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