Mr McDonald said Peterus Johannes Cornelissen, 59, died on Saturday after losing control of his motorbike and crashing into a bank on SH25 near Kopu about 3.35pm.
Mr Cornelissen was airlifted to Waikato Hospital but died a short time later.
Mr McDonald said the deaths were frustrating as they were both avoidable.
The loss of Mr Cornelissen was particularly tragic given police attempts to prevent riders in the area coming to grief, he said.
"One of our officers spoke to another rider at Buffalo Beach near Whitianga shortly before the crash and as he was there they were passed by another group of riders. Two members of the public subsequently stopped and made complaints against the nature of that second group's riding.
"So the following loss of life was a double blow to our staff to hear that this group has gone on to experience such a traumatic incident.
"Our road policing staff work long hours alongside other emergency services trying to keep the public safe and I can assure you they take every serious injury and fatality very personally."
If the earlier crashes weren't enough for emergency services to deal with, first responders were called out again on Sunday to deal with a two-car collision on SH31 west of Otorohanga.
"In this crash two cars collided at the intersection of SH1 and Waitomo Valley Rd. An Auckland couple in their seventies were airlifted to Waikato Hospital with serious injuries while a 75-year-old US citizen appeared in the Hamilton District Court yesterday on two charges of careless driving causing injury in relation to the crash.
"We've now lost nine people on Waikato roads this year in eight fatal crashes. That basically equates to one family every week having to come to terms with the loss of a loved one, not to mention those people facing potentially life changing injuries. The question needs to be asked, what are we doing about it?"
Mr McDonald said from a police perspective his staff would be maintaining their high-visibility presence on Waikato roads endeavouring to keep motorists safe. But the public also had a role to play.
"That's don't drink and drive, don't sit silently in the passenger seat while someone else does and don't tolerate reckless, dangerous or careless driving - the cost is just too much."