These races between Amtrak trains (and freights too) are a fairly common sight in Martinez, Ca. at certain times of the day, on the multi-track main. Check the westbound Capital Corridor and San Joaquin Amtrak schedules, as it is usually these two services that end up racing each other.

This can be observed best along Embarcadero St, off of Berrellessa Ave; or a birds eye view can be had from Carquinez Scenic Drive at one of the vista turnouts on the track side where the trees open up. The park entry gate is closed at sundown, but you can get out of the park up to two or three hours later. Even if you don't see a race, Martinez is one of the hottest "train spotting" locations in the west (44 Amtraks and a dozen or so freights per day - plus lots of industrial drags).

In Oakland, South of the MacArthur Street Station, BART trains race each other on the triple track from the tunnels towards the station, dozens of times every day; best observed from the 34th St. over-crossing, on the south side. Last I saw (2010), parking was still allowed on the bridge.