VANCOUVER -- The patience of Canadian truck drivers stranded at key U.S. border crossings was severely tested yesterday as tight security measures caused another day of heavy lineups, particularly in Ontario.

Frustrated drivers were reported to be asking clients if they really wanted them to spend up to 15 hours at crossings in Fort Erie and Windsor, Ont., waiting to get clearance from U.S. customs officials.

"A lot of people are going to find that they are losing money over this very quickly," said a spokeswoman for Livingstone International Inc., Canada's largest broker and trade services firm.

As stringent searches are expected to become the norm at American border points, companies were being advised to consider alternatives such as rail transportation to minimize the time it takes to get clearance from U.S. customs.

"The best bet for shippers seems to be rail," said Livingstone chief executive officer Peter Luit.

Although some commercial aircraft diverted from the United States are now taking off from Canada, Mr. Luit advises shippers to avoid airlines for as long as the backups and security alerts continue.

"Because rail police are on board the trains, they're not only unaffected by highway lineups, but also clearing faster than other modes of transportation," he said. Rail police are customs officials who travel on trains and process documentation en route.

Canadian National Railway Co. spokesman Mark Hallman said his company stands ready to accommodate any new business that comes its way. But he said it is still too early to speculate on how much extra freight will be redirected to CN as a result of the tie-ups at the border.

"It is unknown how much longer the additional border requirements will remain in place."

However, other export industry officials said rail transportation is not a viable alternative to road travel because it is limited to major corridors and many warehouses are not connected to rail systems.

That's why about 67 per cent of goods crossing the border is shipped by road, compared to 17 per cent for rail and six per cent for air, according to Transport Canada and the U.S. Department of Transportation. The balance is carried by pipelines and water routes.

Meanwhile, Livingstone officials are urging the company's 16,000 client firms to speed up the cross-border transportation process by sending freight documentation ahead of the goods.

"If our clients send us their invoices in advance, we can set up the information with customs before the physical goods actually reach the border," said Larry Hahn, Livingstone's director of regulatory affairs.

Industry officials said shippers bringing freight north into Canada are getting through without too much difficulty. But it is a very different story for those headed south into the key U.S. market.

"If you are trying to move commercial freight, it is slow," said Jane Magagna, vice-president of Northex Cargo Inc. in Brampton, Ont.

At the Fort Erie crossing, 500 trucks were being directed into a race track area yesterday and were being released in groups of 20 at a time.

At Windsor, backups have been so extreme that customs officials said it was impossible to estimate waiting times.

While lineups at key border points in Alberta returned to more-normal levels, transportation officials are bracing for higher crude oil prices that will affect the cost of diesel fuel.