Four fatalities on SA roads due to speed

Four men died in separate accidents on South Australian roads at the weekend, including a driver who ploughed into five pedestrians before hitting a tree.

Superintendent Bob Fauser said speed was a factor in each accident, and drink-driving was possibly involved in two.

Each fatality involved a male driver - one was on a motorcycle - colliding with a tree.

On Sunday night, a 32-year-old driver died in Adelaide after his car hit the pedestrians, injuring four of them, and then a tree.

Supt Fauser said the driver was disqualified, adding "we can just consider ourselves lucky that these pedestrians weren't killed".

A cyclist died on Monday afternoon after colliding with a truck, bringing the year's road toll in SA to 18.