The Crown Prosecution Service (CPS) is expected to give its reaction later to criticisms made at an inquest into the deaths of four cyclists.
Coroner John Hughes questioned why more charges were not brought against driver Robert Harris following the tragedy.
Thomas Harland, 14, Maurice Broadbent, 61, Dave Horrocks, 55, and Wayne Wilkes, 42, died while on a practice ride near Abergele, on 8 January, 2006.
Council officials and the police were also criticised by the coroner.
An inquest jury at Abergele ruled out accidental death and returned a narrative verdict - which delivers factual statements on events leading to the deaths.
In this verdict, the jury criticised the CPS and driver Robert Harris, who crashed into the cyclists after skidding on ice.
Mr Hughes also said he failed to understand why Robert Harris had not been prosecuted for driving without due care and attention.
In their verdict, the jury also said that poor communications between North Wales Police and Conwy and Denbighshire councils had been factors in the crash.
In a damning statement, the coroner echoed the jury's findings and said police and officials had been "most unprofessional".
On a failure to grit roads after calls had been made alerting officials of ice, Mr Hughes said the North Wales Police control room "needs a rethink from top to bottom in their transmission of information and briefings".
"I sat here biting my tongue during the inquest of this most unprofessional state of affairs and I will be writing to the chief constable recommending a fundamental examination of the way they receive and disseminate information and a general re-training of those involved."
Police officers examining the crash scene near Abergele
North Wales Police said they were "carefully considering" the findings of the inquest.
Mr Hughes went on to say there had been a "Berlin Wall" between the counties of Conwy and Denbighshire but that the weather "took no account of lines on maps".
"Some steps have been taken to change things, but it's a pity it's taken four lives to get this movement," he added.
Speaking after the inquest, Derek Barker, chief executive of Conwy Council, confirmed that systems and procedures had already been changed locally in line with what the coroner and the jury had said at the inquest.
The cyclists had set out in pairs on a 60-mile trip between Great Orme and Llanrwst, in what they believed was fine weather, and were wearing helmets.
Around 1000 GMT that day the Rhyl Cycling Club members wound their way along the A547 Rhuddlan Road.
Some time after, four members of the Sunday club lay fatally injured.
Motorist Robert Harris, 47, had been travelling in the opposite direction in his Toyota Corolla on his way to work as a security guard for B&Q. His car skidded on ice and spun out of control, crashing into the cyclists.
The jury heard from cycling club member Jonathan Harland, who had been riding alongside his son Thomas, seconds before the teenager was killed.
While he said he initially felt no anger towards the driver, a statement read to the court on his behalf told how he felt "for many months nothing but anger towards the driver who killed my son and three of my best friends".
A week later, the inquest heard from motorist Mr Harris. He said he had been "very possibly" driving too fast and that he often wished he had died instead.
The inquest heard that he constantly recalled the tragedy and "did not set out intending to harm or even upset anyone".
In August last year, Mr Harris was fined £180 with £35 costs and given six points on his licence after admitting having defective tyres - found not to be a factor in the crash.
Other crucial evidence centred around the issue of road gritting. The jury heard how police had informed Conwy Council's highways department that roads needed treating.
This came after a motorist complained of skidding on a bridge in the Towyn area earlier that morning.
Inspector Jane Banham told the hearing she expected the council to review the state of all roads in the area following that call.
She said an officer asked her a short time later for parts of the A547 near the crash scene also to be gritted due to problems with ice.
But, she told the inquest, she did not contact Conwy Council with that specific request.
A police statement read: "North Wales Police will now consider the findings and the recommendations carefully and at length."