Police say the cause of a serious crash north of Napier on SH2 is a mystery.
Two motorcyclists were travelling single file on SH2 about 10.30am, in fine weather just north of Matahorua Rd's northern intersection with State Highway 2 between Tutira and Napier-Wairoa halfway-mark Putorino.
The front rider realised his fellow traveller was no longer behind him, and circled back to find that his companion had crashed.
No other vehicles were involved in the crash, which closed SH2 for more than three hours and led to a Hawke's Bay man in his 60s being airlifted to Waikato Hospital in a critical condition.
Police are seeking information from anyone who saw the two motorcyclists before the crash, on what was on Sunday becoming a horror Labour Weekend on New Zealand roads.
Police Eastern District road policing manager Inspector Matt Broderick said the crash was one of at least six on Saturday and Sunday in the region, which stretches from the Takapau Plains in Central Hawke's Bay to East Cape.
The Labour Day weekend holiday toll nationwide had climbed to five, two more than for the entire weekend last year.
The trouble on the roads wasn't limited to the crashes. Broderick revealed 19 motorists had been stopped for "significant" speeding offences on State Highway 5 between Eskdale and Tarawera in one eight-hour police shift on Friday.
It was just hours after police pleaded for safer driving over the holiday weekend, amid expectations of heavier-than-usual traffic as holidaymakers revel in taking a break under Level 1 Covid restrictions.
Broderick said crashes had limited the highway "presence" that had been planned, but he warned police would be highly visible tomorrow as holidaymakers headed home.
Sunday's SH2 motorcycle crash happened about 10.30am, in fine weather about halfway between Napier and Wairoa.
The road was closed for several hours, with no available detour and growing queues of holiday-weekend traffic as rescue crews worked on the critically injured man before he was flown by rescue helicopter to Waikato Hospital in Hamilton.
"We appeal to anyone who may have seen these two motorcyclists on this road to come forward to assist us with our investigation," Broderick said.
The holiday weekend road toll by this afternoon includeda man whose ute rolled near Whatatutu Rd bridge near SH2 township Te Karaka, northwest of Gisborne early on Saturday morning.
Another single-vehicle crash closed SH35 on the East Coast on Sunday afternoon.