A PC game by Microprose, Inc.
One of the major improvements of Transport Tycoon Deluxe over the original Transport Tycoon game is the much more sophisticated train management. Where TT knew only simple two-way signals, TTDLX allows one-way signals. These signals permit a train to pass in only one direction and are essential for the following design hints. The suggested designs WILL NOT WORK in TT Classic - but you are welcome to try anyway...
1. The Track
Unsually, one needs one track per train. This works well for transporting a few valuables from A to B and vice versa, but imagine the following scenario: you have a coal mine that yields 1080 tons of coal per month. You want to transfer that coal to a power plant 60 or 70 squares away. To carry all that coal, you need three or even four full-size coal trains (engine and eight wagons.) Now, to build four parallel tracks is expensive and impractical. More often than not, there won't be enough space for four truly parallel tracks, because there is some obstacle in the way. Additionally, local authorities get really mad at you when you chop too many trees. Building tracks is somewhat expensive, and finally, too many tracks in one place look ugly, don't they? In the given example, it is however possible to run four or even five trains on only two tracks. The trick is to have one dedicated track for each direction.
Place the signals so that there is always just enough space between them for one train. This way, you avoid having trains waiting a long distance away because part of the track is blocked. A train waiting at a red light will get bored after a while and turn around. On this kind of track, it won't get far, because there is a one-way signal in the wrong direction right behind it. So the train will turn around once more, until the track is free again. Usually, however, there won't be too many traffic jams in our scenario. Ideally, one train is loading, one is unloading, one rolls towards the mine, and one towards the power plant.
2. The Station
First of all, build big stations. Even if you don't need all that space right away, odds are that the town nearby will grow, or the industry you service will increase production. Building a huge 4 * 5 station will save you hassle and extra expenses in the future. A standard station should look like this:
Note that there is a depot at the end of each track of the station. This has several benefits over having depots placed along the tracks: trains in TTDLX don't change direction unless they have to. This means that a train that rolled into the station will go to the depot before it leaves again. Since trains (and road vehicles, but not ships, alas) get serviced automatically once they enter a depot, your trains will always be in top condition and have the highest reliability possible when they leave the station. Frequent breakdowns are the biggest threat to an otherwise well constructed railway system.
On the other end of the station are tracks with two way signals. They prevent the trains from interfering with each other. A nice feature of the game's AI is that an incoming train will always choose an empty track if possible. Next to those signals is the intersection. It is vital that an incoming train can reach each track of the station, and that an outbound train can reach the outbound track *from* each track of the station. Furthermore, one should try to keep the intersection as small as possible. Only one train at a time can use the intersection, so, if a train breaks down there, it blocks everything. Behind the intersection, standard track is appended.
The standard station works well up to a certain amount of traffic. The worst case scenario is this: Four trains are already in the station, loading or unloading. Now a fifth one arrives. It will enter the intersection and either roll off in the direction it came from or place itself in front of the most convenient track of the station, i.e. the one directly in front of the incoming track. This track is not necessarily the one that will be available next. Therefore, it can happen that three trains are waiting to exit the station, one is still loading, and one blocks the intersection - total traffic jam. Finally, the last train will have finished loading. Once it has entered the depot, the incoming train will enter the station. Whereas the first three trains can now leave one after the other, train four has to wait in the depot until train five has finished its business. This chaos can be avoided with a RoRo (roll-on / roll-off) station.
Trains arrive on the inbound track. The first train will choose the most convenient track (the one on the bottom of the picture.) While it is still loading/unloading, the next train arrives. Since the favoured track is blocked, it will choose the one right above it, and so on. A train that is ready to leave will do so on the right side of the station as seen in the diagram. There is less opportunity for congestion since inbound and outbound trains never use the same track in this type of station. Several things to note: Again, keep intersections as small as possible. Furthermore, it is necessary (for an unknown reason) to use two way signals whenever you want a train to choose between two tracks. That's why there are two-way signals in front of the station. And don't forget to have a standard station at one end of your route, or your trains won't get the service they need.
3. The Pipelined Public Transport
You can place standard stations in every town on the map and connect them all with one pair of standard track. This way, your passengers can reach every place by using rail exclusively (I know, the game doesn't simulate this, but it's a neat idea anyhow.) If one town generates more passengers and mail than expected, just redirect an existing train that hasn't enough business. It will find the way by itself!
There was a map of Wales included with my copy of TTDLX. On this map, I connected four or five high-yield coal mines in the top left region to a single power plant near Cardiff. Approximately 20 trains roll to a single RoRo station at the plant (although I later added a second station there.) I quickly found out that standard track can't take this kind of traffic. There's always one train that will break down, blocking traffic. So I developed a monster rail super highway with four lanes of incoming and outbound traffic.
It sure is ugly, isn't it? But it works! Whenever a train breaks down in an intersection, the following trains line up nicely on the adjacent tracks. If a train breaks down in between signals, it gets bypassed. (Actually, one should place the intersections further apart than shown in the picture for this very reason.) It's fun watching the trains find their way. This method also works with only two or three lanes in each direction. Or five. Or ten. Or a hundred... (manic laughter) But I digress.
Wolfgang Preiss' Article on
Advanced Railway Construction