This past December, ACE completed the last phase of installing (PTC) Positive Train Control on ACE equipment which is a federally mandated safety system. With the implementation of PTC there have been some technical issues that have caused delays to the service. ACE and its partners have been working to resolve these issues and we should see a reduction and elimination of delays related to the system soon. We understand the importance of arriving on-time to your station and we will continue to work on providing reliable and safe service.
If you want to know more about PTC, Union Pacific has a really nice breakdown of everything involved here: https://www.up.com/media/media_kit/ptc/about-ptc/