Alberta drivers will be paying five per cent less for basic car insurance starting Nov. 1 but it’s not known what their final insurance bills will look like since the additional coverage purchased by most motorists is not included in the decrease.

The Automobile Insurance Rate Board announced Thursday it is reducing premiums on mandatory automobile insurance, primarily due to a decreasing number of bodily injury claims.

However, the board does not set rates for optional insurance, which includes collision and comprehensive coverage. About 80 per cent of Alberta drivers carry such coverage, which makes up about 45 per cent of total car insurance bills.

Mandatory insurance rates have decreased about 23 per cent in Alberta since 2004, while optional rates have increased seven per cent in the same time period.

The average cost of total insurance premiums, including mandatory and optional, has gone from $1,023 in 2005 to $1,092 in 2009 in Alberta, said Merle Taylor, the consumer representative on the AIRB.

“I think consumers will be quite pleased,” with the most recent decrease in mandatory coverage rates, she said.

The decrease in mandatory car insurance is the result of a steady decline in bodily injury claims, which is the result of safer cars and consumer behaviour, Taylor said.

Alberta’s cap on soft-tissue injuries, such as whiplash, is also seen as a major contributor to the decrease.

The five per cent reduction in mandatory insurance premiums will save Alberta drivers an average of $30 per year, the AIRB said.