Tuesday, October 27, 2009

An example of Normal Speed Rail

In the UK, Virgin Trains cover the 200 mile distance from London to Manchester in about 2 hours (with the fastest express being 1:58), for an average end to end speed of 100 mph. And this is done on a railway that mostly runs on a 19th century alignment, and has a top speed of 125 mph, and which is shared with all manner of local commuter and freight trains.

In the US, that sort of speed would imply a travel time of somewhere around 4-4.5 hours for LA to San Francisco, 9 hours from New York to Chicago, 10 hours from Denver to Chicago. The latter two city pairs are particularly interesting: it's unlikely that high speed rail will be built over such distances, at least not anytime soon. But with enough incremental improvements, it's possible to get travel times down to a point where overnight trains are a reasonable option for getting across one-third of the country.


  1. The joys of 125mph running is that it doesn't require expensive in-cab signalling, which higher speeds do.
    In the USA, the critical number is 110mph - above that, and all level crossings have to be grade seperated. The US's lower popualation desnity and lack of local trains on routes like Denver-Chicago means that 110mph trains could spend most of their time at top speed, and so still have an average sped of around 100mph.

  2. In the US, anything 80 mph or faster must use some form of automatic train stop, either the now rather obsolete intermittent inductive train stop, or continuous cab signals, which are fairly common on the East Coast, and not considerably more expensive than putting in regular signals. I believe that above 125 mph, fancier systems like ACSES are required. Regular grade crossings are allowed up to 110 mph, and ones with a physical barrier (presumably like the ones found in Russia) are permitted up to 125 mph. In the UK, the speed limit is 125 mph with AWS/TPWS, with higher speeds requiring cab signals (and only found on the one high speed line). I don't think there are any restrictions on level crossings, although the ones on 125 mph lines tend to have CCTV, and need to be confirmed as closed before the signals clear for the trains.