The Oregon Department of Transportation (Odot) estimates that it will cost $US 10.4m to continue operation over its next bi-annual funding period which runs from June 30 to June 30 2017, which was negotiated down from the $US 20m requested by Amtrak. Former Oregon governor Mr John Kitzhaber included a $US 10.5m allocation in his budget request before his resignation on February 18 following a misconduct charge.

This was subsequently cut to $US 5m in the Joint Ways and Means Committee budget in an attempt to get Odot to allocate funding directly rather than using general state funds. However, Odot declared that it would not be able to maintain the existing service at that level of funding. The proposed state contribution to the service is 0.2% of the state's transport allocation, with Oregon is set to allocate $US 1.6bn towards road in its two-year budget.

Officials have indicated that if Odot cannot find the funds alternatives will be sought and that they are optimistic that it will remain operational.

However, if the Cascades service is lost, the Portland – Eugene corridor will only be served by the once-daily Seattle – Los Angeles Coast Starlight despite Oregon investing $US 38.4m from 2009 Federal stimulus funds in two 13-car Talgo 8 trains to boost capacity on the Cascades service.

The issues surrounding funding in Oregon mirror similar circumstances for loss-making Amtrak services in Illinois and Indiana.

Illinois governor Mr Bruce Rauner has proposed reducing its state subsidy for the state's four Amtrak corridors from $US 42m in 2015 to $US 26m in 2016, threatening to cut back the level of service on the routes despite rising traffic and improving reliability. It also places questions over future funding for enhanced services on the Chicago – St Louis corridor. Work is continuing on the $US 1.5bn infrastructure enhancement project which will increase speeds to 177km/h with eight services per day proposed on the route from 2017.

In Indiana, the future of the four-times a week Indianapolis - Chicago Hoosier State service is also in jeopardy following a disagreement between the Indiana Department of Transportation (Indot) and the Federal Railroad Administration (FRA) over who was responsible for safety.

Indot argued that FRA's insistence that the state act as the rail carrier under the proposed partnership between Amtrak and Iowa Pacific Holdings, which included a $US 200m liability in case of an accident, was too expensive to keep the service operating and threatened to end the service on April 1.

This deadline was subsequently extended by 30 days and on Monday Indot said that it had reached an understanding with FRA under which Amtrak and Iowa Pacific Holdings would assume responsibility for safety with Indot overseeing this arrangement. The deal is not yet finalised and requires inspections by Amtrak and the FRA as well as US Food and Drug Administration inspections of Iowa Pacific equipment to proceed.

"INDOT and the FRA share the guiding principles of access to safe mobility," says INDOT commissioner Mr Karl Browning. "Based on these guiding principles, we are both committed to a path toward continuing the Hoosier State service."