Why is it that trains prefer to run like traffic on a two lane road on double track?
Is there a reason why trains pass each other on the left?
The way your question is worded is somewhat confusing. But the answer you’re looking for might be that not all double-track is “right-hand” running. The C&NW standardized on left-hand running. But in North America right-hand is the norm. Other threads have discussed this at length. You should search the site for this topic. There’s a lot of historical info.
The reason the CNW ran left-handed is because most of its stations were built on the north side (facing south) when it started as the single-track Chicago & Galena RR in the late 1840s and early 1850s. When necessity dictated more capacity, they went to double (and triple) track later on. The only place to put the second main was outside of the original main in realtion to the stations. So they ran left-handed because that’s where the stations were for people waiting to travel to Downtown Chicago. Going west no stations were needed (on the south side).
Metra and the UP still run that way today.
At Daggett CA on the BNSF transcon they run just as as our highways do except when there is some trackwork or they are running a Z train around a lower priority train. On the UPRR in Utah between Ogden & SLC they also run the trains just like as you would drive on any USA highway [:D]
I think a lot of the tradition comes from having the engineer’s side of steam locomotives being on the right and wayside signals being on the right. When multiple tracks were added the easiest way for the track and signal layout to fit in the confines of the right of way is to continue to put the signals on the right to save space. Someone may know why steam locomotives were constructed with the engineer’s seat on the right.
I think that the tradition just began on the right, probably because thats the side of the road we drive (even cariages) on, so that’s the side we stuck with. Signals are best when not between the tracks, because they get in the way, so they went off to one side. Putting them on the same side as the station made sense, because a steam locomotive engineer can only really see out one side. Additionally, most switches and sidings would go off to one side, usually away from the tracks. So the train runs on the right, where the engineer sits where he can see the signals, sidings, switch targets, and stations. I suppose everything could be transposed to the left, and it would work the same, we’re just used to the right.
The way trains run on double or multiple track is specified by the rules of the particular railroad and is known as “current of traffic”. Most railroads specified the current of traffic to be the right-hand track, the C&NW being the most noted exception. When double track had signals installed, they were for one direction only - whichever was correct for the current of traffic. If there was a third track, its current of traffic was specified in the timetable special instructions. Four tracks and more, same thing,
Then, when Centralized Traffic Control came along, it became possible to signal tracks for operation in both directions, and current of traffic was superseded. However, it wasn’t uncommon to see a stretch of double track with CTC on one track and current of traffic on the other, to take care of some specific operating conditions.
The rules governing the authorization of trains to operate under current of traffic or CTC were, of course, found in the operating rules and the timetable special instructions. Timetable refers, of course, to the employees operating timetables, not the public timetables.
Old Timer
Am I right in thinking a lot of American railroads now have reversible signalling on most double track lines, enabling trains to be signalled in either direction? It’s becoming more prevalent in Britain. Some years ago I can remember travelling across London on the Western London Link line (which links the different lines North and South of the River Thames) and our train, the Brighton - Glagow “Sussex Scot” was running neck and neck with an empty Eurostar heading for the depot in N. London were these trains are maintained.