One of Police Scotland’s most senior officers urged holidaymakers to be aware of the additional dangers of driving fully-laden cars on congested and unfamiliar routes.
These included increased braking distances and more slow-moving vehicles such as caravans, motorhomes and tractors.
A 15-year-old girl and three motorcyclists were among those who died in the crashes since last Saturday, along with two men in a two-car collision in Ayrshire on Thursday.
Traffic on major roads is expected to increase further with the start of the English schools’ summer holidays this weekend.
To coincide, Police Scotland will take part in a new Britain-wide two-week speeding campaign from Monday, with increased patrols across the country.
Assistant Chief Constable Mark Williams, the force’s executive lead for roads policing, told The Scotsman: "The pressure on the road network will be as high as it’s been for a long time.
"It’s the school holidays and people will be arriving from England and Wales – all of that cumulatively makes for probably the busiest summer on Scotland’s roads for a number of years.
"Therefore we would expect to see a greater number of road accidents, and that’s sadly what we have observed over recent weeks with the number of serious and fatal accidents.”
Mr Williams said factors in fatal crashes included excessive speed on corners, poor judgment, such as in overtaking, and driver distraction.
He advised motorists: “ A lot of this is about preparing yourself for the journey ahead.
"If you are driving on rural roads you don’t know, remember they are often more challenging and there can be hidden dangers such as agricultural traffic, tight bends and poor surfaces.
"If you have got a heavily-laden vehicle, such as with a family, luggage and a roof box aboard, it will handle differently, so simple things like making sure your tyre pressures are right are important.
"It might take longer to stop, and when you turn, the car might not behave as it would do if you were on your own, commuting to work.”
Mr Williams said incorrect tyre pressures could cause poor handling if the vehicle had to make an emergency stop or swerve.
In the latest road deaths, two men, aged 65 and 35, died when two cars collided on the A713 near Patna in East Ayrshire at 4.40pm on Thursday.
The 15-year-old girl died after a minibus collided with a lorry on the M74 near Annan in Dumfries and Galloway at 4.45pm the previous day.
A 47-year-old motorcyclist died in a collision with a car on the A939 near the Lecht Ski Centre in Aberdeenshire at 2.10pm on Sunday.
A 32-year-old motorcyclist was killed when he collided with a tractor on the B778 near Stewarton in East Ayrshire at 11.10am on Saturday.
The same day, a 56-year-old motorcyclist died in a collision with a car at 3pm on the A82 in Fort William.