U turn的优先级最低，比左转还低。没事就无所谓，出事100%全是u turn的错，不论别人是怎么开的。无论是路口还是路中间。
As it turns out, the U-turn rules in Ontario are pretty straightforward. Unless you're on a railway crossing or somewhere where oncoming traffic can't see you, you can usually make them anywhere there's not a sign banning them.
"At an intersection, it might say, 'No U-turns,'" said Sgt. Kerry Schmidt, with the Ontario Provincial Police Highway Safety Division. "But otherwise, as long as it's safe – as long as it's not on a blind corner, a crest of a hill of in front of a railway crossing – you can do them."
Section 143 of Ontario's Highway Traffic Act (HTA) provides the specific restrictions; violations result in a $110 fine, including fees, plus two demerit points. In 2015, there were 119 violations in Ontario, the Ministry of Transportation (MTO) said in an e-mail.
Otherwise, you can make U-turns at intersections or in between intersections, as long as you signal and make them safely.
"You can't interfere with any traffic that may be approaching – if you do you may be charged with other offences, although not necessarily the U-turn offence," said Const. Clint Stibbe, with Toronto Police Traffic Services.
Two other sections of the HTA – section 141 and 142 – "stress the responsibility of all drivers to ensure that they make safe driving decisions when making turns," the MTO said.
