A coalition of agriculture associations says the grain industry is dealing with deteriorating rail service with an 11 per cent shortfall in the supply of railway cars.

The Ag Transport Coalition has released a report saying that the railways have failed to supply more than 11,000 cars that were ordered in the first five months of the crop year.

The report also says the shortfall has continued to grow each week.

Wade Sobkowich, executive director of the Western Grain Elevator Association, says he's concerned that the demand for railway cars is exceeding the supply.

He adds that service is better than last year, which saw months of railway backlogs after a bumper grain crop.

Sobkowich says the improvement is partly because shippers were able to move higher volumes of grain in August compared to the previous year.

He adds warm weather has also helped -- cold temperatures can affect brake systems, which forces railway companies to use shorter trains.

Sobkowich says overall railway transportation needs to be revamped to be based on demand.