Friday morning saw 10 road traffic accidents along a single motorway corridor.
Police had initially said “a few” accidents were slowing down traffic.
As the morning wore in this grew to an estimate of half-a-dozen, then to eight confirmed accidents.
Finally, the tally of crashes between 5am and 11am reached 10.
The Ambulance Service attended two of the accidents, each involving a single woman.
Neither of their injuries were thought to be life-threatening.
The motorway runs between Dungannon and Belfast, and the PSNI had warned of treacherous driving conditions, particularly towards its western end.
The DRD said that the M1 had been gritted from 9pm the night before, then again at 3.30am – with extra operations laid on later for the stretch between western junctions 12 and 14.
There was also a two-vehicle collision on Ballysallagh Road, Bangor. Two individuals suffered injuries which were not thought to be life-threatening.
There was also a two-vehicle collision in Bangor.
It happened on the Ballysallagh Road and resulted in two individuals being hurt, although their injuries are not thought to be life-threatening.
That road was closed after around 8am, and re-opened at around 10.30am.