GG-1 said:
I am focusing on the OT performance of the Zepher because my connection to 59 is important. [...]
I am not sure if the schedule is showing the normal route. I am also unclear as when the padding is subtracted from the arrival estimate. for example a few minutes ago the 6 was listed as 4hrs. 32 min. late yet the estimated arrival in chicago was 2 hrs. 25 min. late. is this with the padding subtracted.
Route: Yes, the Zephyr is operating over its normal Moffat Tunnel route. The last planned construction detour via Wyoming should have been on Friday 30 July.
Arrival time estimates: Yes, the Amtrak web site does seem to account for schedule padding when calculating predicted arrival times. My guess is that this is to protect passengers from missing the train if they see that a train is running late and assume that it will remain as late for the rest of the route.
Padding: In the specific case of the California Zephyr's approach to Chicago, it is scheduled at Naperville (NPV) at 2:09 pm and at Chicago (CHI) at 3:32 pm. But it is only 28 miles from NPV to CHI over the BNSF "racetrack," most of which is triple track with a 70 mi/h speed limit. The train can easily cover this distance in 35 minutes. (Indeed, the outbound schedule allows 34 minutes for CHI-NPV.) BUT if the Zephyr is arriving on a weekday afternoon during the outbount commuter rush hour, it may have to run at 30 mi/h all the way from NPV to CHI behind a local commuter train making all stops. Time may also be required to remove the mail/express cars from the train as it arrives downtown. (This is definitely done on the Chief; I'm not sure if it is standard practice for the Zephyr as well.)
On Sunday I was aboard #6(13Aug) from western Iowa to Chicago. As others have mentioned, the westbound train arrived in California very late causing a late eastbound departure. From at least Denver eastward (when I began calling Julie), it was running 6.5 to 7.0 hours late, but it ran well and lost no more time in 1000 miles across eastern Colorado, Nebraska, Iowa, and Illinois. At NPV it was still 7 hours late, but on a Sunday evening with few trains on the racetrack, by CHI it was only 6:07 late, having made up nearly an hour in its final 28 miles (due to the padding).
Your trip: There's really no way to predict what will happen on the day of your particular trip in September. There are so many variables in the 4876 miles and 6 days that trainset is on the rails between departing CHI and returning to CHI. Sunday it was over 6 hours late; tonight it left Denver less than an hour late. All I can say is: good luck!