SENIOR police have vented their frustration over WA’s skyrocketing road toll after four people were killed in a horror 12-hour period.

Six people have died on WA roads since Thursday afternoon, when two Chinese tourists were killed in a head-on collision south of Geraldton.

WA’s road toll now stands at 97 — 58 deaths in the country and 39 in the metro area, well above last year’s July 31 figures of 82, 47 and 35 respectively.

Det-Sen Sgt Steve Potter, officer in charge of the major crash investigation section, said it wasn’t just the victims and their families who were devastated by the carnage.

“It’s always traumatic for all the emergency response people — the police, the fire and the ambulance people who have to deal with it — they don’t get used to it,” he said. “It affects them and also affects their families long-term.”

He said speed was a factor in two of the three accidents.

In the Kimberley, one vehicle carrying six people from one family rolled along the Gibb River Road, about 180km west of Kununurra, and 15km east of the Ellenbrae Station, just after midnight.

Three people were transferred to Kununurra Hospital but two adult passengers died at the scene. A six-year-old child is expected to be flown to Darwin for further attention.

About the same time in Perth, police were called to a single-vehicle crash along Chittering Road, Bullsbrook. A 45-year-old Bullsbrook man lost control of his Holden Statesman while negotiating a bend and slammed into a tree about 200m east of Hurd Road. He died at the scene.

About 7.30am yesterday a car lost control driving at speed along the Roe Highway at Forrestfield, rolling down a small embankment.

Passing motorists tried to help the two men in the car until emergency services arrived. One died at the scene while the other was rushed to Royal Perth Hospital in a serious condition.