Donner Pass Question - General Discussion (Trains.com) - Trains.com

The majority of the line over Donner is still double track. Having the second track in operation, even though the traffic no longer warrants two lines, has allowed train flow to operate uninterrupted after two derailments this winter, plus a flanger went on the ground during the last storm. Union Pacific has shown no interest in further dismantling the second track. In fact, UP has had a lot of trouble keeping the Feather River line operating in bad weather with slides, etc., and there has been rumors that more and more traffic is going to diverted from the Feather River Canyon to Donner. Where the old double track was directional running, the line is currently all CTC and with only a small amount of single track running, could probably handle more trains today then prior to the CTC installation.

When the UP bought the WP in 1982 all the former UP transcon traffic was diverted to the former WP line through the Feather River. The average train count over Donner went from 20 plus trains per day to 6 per day. At the time it probably made sense with only 6 trains plus Amtrak to cut out the second track. Union Pacific has a big project in Reno currently that is dropping the double track main line below ground to eliminate grade crossings through the downtown. UP has stated that they expect train counts to continue to increase in the near future, so possibly when this project is completed the bulk of the transcon traffic will again be using the Donner Pass route.