Freight trains in Europe are much faster[1] -- but that could be because they often need to fit in with the schedule of passenger trains using the same lines (which themselves require the track to be maintained to a high standard).
[1] Citation needed, I only have observations of them going at a decent pace through stations I'm waiting at.
http://www.coyoteblog.com/coyote_blog/2008/02/european-vs-am...
That's probably exactly why freight trains are faster in Europe:
> In fact, the freight rail system is so efficient that to some extent we've obviated the need for the Panama Canal. Many Asian container ships bound for Europe actually make port in Seattle or Vancouver, offload their containers onto trains which shoot across the country to New York or another eastern port where they are reloaded on ships for the trip to Europe.
Though I suspect soon enough the Northwest Passage will be clear for enough of the year that most freighters will just sail through the Arctic. Perhaps both Panama's government and North America's railroads should be pushing hard for a carbon tax.
Intuitively, I'd expect that once the train has accelerated, it will keep its momentum very nicely, and (if electric) can easily return energy if it does need to slow down.
I can't find a real-world coasting distance for a train on level track, only reports during accidents/near misses -- 5km under emergency braking on a slight downhill slope, for one! [2]
[1] https://en.wikipedia.org/wiki/Rolling_resistance [2] https://www.gov.uk/government/uploads/system/uploads/attachm...
Then to stop it will take t = v/.0004g which means that you will travel vt/2 in that time.
For example, if a train is cruising along at 30 mph (44 fps) then it takes 44 ft/s / .0004(32.2 ft/s^2) = 3416 seconds to stop which means that the train travels 14.2 miles under ideal conditions.