Alpine to El Paso is 3hr:16m, 218 Miles, about 67 MPH. The return is much more drastic, with FIVE hours and 20 minutes allocated. That's an average speed of 40MPH. 200 miles is an awful long distance to go 40 mph...
Between El Paso and Alpine is also the time zone change between the Mountain time zone and the Central time zone! So going eastbound, you lose an hour and that accounts for 1 hour of the extra "time"!
And westbound, you gain an hour and that accounts for 1 hour of the extra "time"!
So the way I see it, one way is scheduled for 4:16 and the other way is scheduled for 4:20!
