I've been fortunate to have ridden behind mainline steam several times, once between San Jose and Sacramento and return behind SP Daylight 4449 in 1992, Santa Fe 3751 to San Bernardino three or four times, 3751 to the Grand Canyon in Arizona,then once to San Diego from LA on a Saturday day trip with my wife. Nothing like the near riot it causes along freeways, neighborhoods, passing through urban centers and along the ocean at speed. The San Diego trip is on Amtrak trackage, and the usual speed is 80 MPH. It had no problem maintaining track speed. The last steam trip I went on with my wife was between Union Pacific 4014 from Colton to Barstow uphill through Cajon Pass about three years ago. That big monster mastodon had no problem hauling over 20 passenger cars, two extra water tenders and a couple of modern diesels for dynamic braking when descending the pass. Lots of Youtube videos on all three of those locomotives. It's neat to see the past relived like that.