The $4,000 cap was brought in by the government in 2004 to save private insurers millions of dollars on injury claims in exchange for lower premiums for many drivers.

It was challenged by Pearl Morrow and Brea Pederson, who were left with chronic injuries after two separate car crashes.

A Court of Queen's Bench judge ruled the cap violated their charter rights, but the Alberta Court of Appeal upheld the cap.

The Supreme Court's refusal to hear the case means the Appeal Court's decision stands.

Alberta Finance Minister Iris Evans says in a statement that the decision shows the government has struck a fair balance between people who pay insurance premiums and those who are injured in accidents.

The groundbreaking case originally stretched out for weeks in a Calgary courtroom. It focused on regulation that then premier Ralph Klein imposed - with very little public debate - on soft tissue injuries that don't show up in X-rays.

The lower court judge ruled that the insurance payouts for the two women should rise to $21,000 for Morrow and $15,000 for Pedersen.

Several legal groups, including the Canadian Bar Association, had supported the women's case, arguing at its essence it involved the right of everyone to access the justice system to determine compensation.

Randy Bundus, general counsel with the Insurance Bureau of Canada, said the case ends the uncertainty for insurance companies and ensures that other benefits brought in with the savings from the cap, such as higher coverage levels for other injuries, remain in place.

He said the cap only applies to damages from pain and suffering and that higher amounts can be achieved for economic losses from injuries.

In order to have a properly functioning system, the government ad to draw a line somewhere, Bundus argued.

“No matter where the government rew the line there would be somebody just ... outside of the line, they would feel that was unfair,'' he said.

“The government had to draw the balance somewhere, they had to balance affordability of premiums with proper recovery for victims.''

Three other provinces - Nova Scotia, New Brunswick and Prince Edward Island - have similar caps, he said, adding an appeal court in Nova Scotia recently also upheld their regulations.