New Brunswick motorists are scratching their heads after gas prices took a tumble in the neighbouring Maritime provinces.

Drivers in Nova Scotia woke up to find gas prices had dropped by 5.3 cents per litre overnight, after the province’s Utility and Review Board invoked its interrupter clause.

Prices also fell on Prince Edward Island, where the province’s Regulatory and Appeals Commission approved a reduction of 7.5 cents per litre.

But it was a different story in New Brunswick and motorists there are asking why their own interrupter clause hasn’t kicked in.

“You drive your vehicle around and $100, or $115 every fill is a lot,” says Saint John motorist Paul Crowdis.

Regular self-serve gas is selling for roughly $1.27 per litre in Saint John Wednesday, which is a few cents more than in Nova Scotia or Prince Edward Island.

New Brunswick’s interrupter clause has been triggered before, but the province failed to follow in its neighbours’ footsteps this week.

The legislation governing when the interrupter clause can be used to raise or lower the cost of gasoline is different in New Brunswick, where the price shift in gasoline markets must be at least six cents per litre before the clause can be invoked.

There is also a timing issue, if the market swing happens too close to the regular price set Wednesday at midnight.

“The regulations say that if on Tuesday, that six cent swing happens, there isn’t an interruption,” explains David Young, a spokesman for the New Brunswick Energy and Utilities Board. “You just set the price as you normally would.”

Prices are expected to drop overnight in New Brunswick, but even with the pending decrease, many motorists say a fair price would be closer to $1 per litre.

“To see it around that mark again, the dollar mark, oh my gosh, that would make all the difference in people’s lives without a doubt,” says motorist Laurie Greer.

While the price of diesel is also expected to drop, the decrease won’t be as significant as the drop in gasoline prices.

With diesel already selling for 16 cents more than gasoline, the price gap between diesel and gasoline is expected to widen even further.

With files from CTV Atlantic's Mike Cameron