B.C.’s controversial automatic roadside prohibition scheme — touted as the toughest anti-drunk-driving law in the country — was unconstitutional when it was introduced in 2010, the Supreme Court of Canada says.

In two related decisions Friday, the court agreed the regime was regulatory legislation that balanced individual liberties against the protection of the public, placing greater weight on the public good.

But it did not have sufficient oversight protection for drivers for its first two years and that version was struck down meaning penalized drivers may get reimbursed.

“In the circumstances, I agree with the chambers judge that the ARP [automatic roadside prohibition] scheme as it existed ‘does not minimally impair the right of a driver to be free of unreasonable search and seizure,’” Justice Andromache Karakatsanis wrote for the majority in the main ruling.

“I conclude that the former ‘fail’ branch of the ARP scheme is not saved under section 1.”

In a partial dissent, Chief Justice Beverley McLachlin said the law was fine.

The province’s purpose in enacting the scheme was not to oust the criminal law, the seven justices agreed, but rather to prevent death and serious injury on roads by removing drunk drivers and deterring impaired driving.

The law was consistent with a modern approach to federalism, the court added, which recognizes overlapping powers are unavoidable.

However, the majority agreed with the trial judge that the initial law breached the search and seizure protections of the charter.

The legislation was subsequently amended in 2012 but the court noted it was not giving a constitutional ruling on that law.

“It is possible the new law is sufficient and the court has maybe indicated it is, but someone can challenge it,” said Vancouver lawyer Shea Coulson.

In the original law, the court said the review provisions did not offer reasonable protection against abusive exercise of the state power to intrude on the individual’s private sphere, having regard to the nature of the scheme and the privacy interests at stake.

The court also had been asked to decide whether the law overstepped the bounds of provincial legislative powers and invaded federal jurisdiction. It did not.

Justice Karakatsanis said provinces have an important role in ensuring highway safety, which includes regulating who is able to drive and removing dangerous drivers from the roads.

Thus, from a division of powers standpoint, the legislation is valid.

“It establishes a common standard for removing drivers from the road who pose an elevated risk to others. It also serves to deter drunk driving,” the justice said.

The amended scheme requires that a police officer inform a driver of the right to request and be provided a second test on a different approved screening device, and, where two samples are provided, the lower of the two results is the basis for a driving prohibition.

“It is the status quo but we’ll keep on the battle from case to case to get better clarity in the law,” Vancouver lawyer Paul Doroshenko said.

“It was a revolutionary piece of law. There has been lots of suffering for many people as we work these matters through the court. I would have preferred that the government pass a constitutionally valid law from the start.”