A woman who witnessed horrific sights after one of the collisions has suffered nightmares, insomnia and been off work since her ordeal, Scotland on Sunday has learned.
Police Scotland said others might never drive again, or couldn’t stop thinking about their experience.
The force urged drivers to be aware that the far-reaching impact of serious road crashes included on members of the public who suddenly found themselves with the harrowing task of trying to help victims until the emergency services arrived.
Chief Superintendent Louise Blakelock, its head of road policing, said: "I’m always keen that never gets lost because some people will never recover and will never forget what happened to them that day.
"That’s one of the consequences that people don’t think about.”
A 24-year-old aviation worker who was first on the scene of one of the latest crashes, along with his 21-year-old girlfriend, after he saw it happen in his rear view mirror, said: “She has not been able to sleep.
"She’s having nightmares, she’s not dealing well with it.
"What she saw was not easy for a 21-year-old to take in.”
Chief Superintendent Louise Blakelock said members of the public were almost invariably first on the scene of such crashes.
She said: "They will have to provide first aid, phone 999 and try and manage the scene until the arrival of the first emergency service.
"Very often, they’ll never have had to be involved in anything like that at all.
"It could have a long-term impact on their mental health."
She said they were advised to see their GP if they were struggling to cope.
She said: "We also do a lot for our police officers separately, which is why we are so conscious of trying to support witnesses because they are often seeing what we are seeing when we get there.”
Among the latest fatalities was a 25-year-old male driver who collided with another car on the A947 near Oldmeldrum in Aberdeenshire and a 56-year-old female passenger of a car which collided with a tractor on the B9128 in Angus, both on Wednesday.
On Monday, an 18-year-old male car driver died when he collided with a van on the A96 between Keith and Huntly, two days after a 57-year-old motorcyclist died on the M74 near Lesmahagow in South Lanarkshire in a collision with a car and another motorbike.
They followed three motorcyclists, two people in cars and a 15-year-old girl in a minibus being killed in a series of crashes across Scotland over the previous week.
Chief Superintendent Blakelock said no explanation had been found for the cluster, but a factor could be increased holiday traffic because of restrictions on travelling abroad, which police expect will make Scotland’s roads their busiest for years.
A spokesperson for road safety group Brake said: “Each death or catastrophic injury on Scotland’s roads causes untold heartache and we should not underestimate the impact on first responders, witnesses, and the emergency services.
"These experiences are harrowing for everyone involved and we must ensure support is available for those who need it.”