Once you've got dual tracks in place, you'll run into a problem that can get quite complicated - designing fast intersections. Getting the trains from station to station as quickly as possible is one of the most important factors in maximising profits (we've already looked at this when we were thinking about the depots) - and poorly designed intersections can have a terrible negative effect on this.

    After a few 'years' of gameplay and a little railway construction you'll no doubt end up in a situation where different pairs of tracks meet, and the trains running on them need to share the two routes. The problem is connecting the different pairs without causing both sides to get congested.

    Having all the track crossing over like this is not a good way to do it - only one train can occupy the central track at a time (regardless of which way they are going) meaning other trains will queue up while they wait for their turn to use the intersection (not unlike the problem encountered with "passing loops").

    The best way to connect routes like this is by going underground to aviod the crossover. This minimises the size of the intersections as well as separating the different lines. ie A train going one way doesn't have to wait for a train going the other way.

    Take particular note of the fact that tunnels have been used instead of bridges to cross the track. This seemingly unimportant feature of the setup has great significance later in the game as the trains start to speed up - the bridges in the game can only handle cetrain vehicle speeds, so, when any train that has a top speed that is greater than the bridge it is crossing, it's speed is reduced to whatever the bridge can handle. If on the other hand it goes through a tunnel, it maintians its speed since tunnels are on the ground.

    Sometimes you'll come across a situation where you'll have a true crossover with track going in all four directions. The simplest, cheapest and quickest (to build) solution is this:

    obviously it is not the best solution - as I have already mentioned, crossovers are horrible, horrible things, and ways to make them faster can be found. Here is what is generally considered to be the best crossover, which works like a highway clover-leaf.

    This design, while appearing to be a little contrived and over the top, is the most effective way of providing access to all directions from all other directions. Note that there are at least 5 squares of track between each of the signals that lead to the main lines - enough room for one (maximum length) train to wait for the track in front to clear, without blocking the intersection behind it.

    Another design that can also come in handy is a thing called a "slip switch". These were the staple of railways in Transport Tycoon Original and also have applications in the Deluxe version. First, let's have a look at what a "slip switch" is:

    Nothing too fancy and something that you've surely seen before. On the left is a "slip switch" using "two-way" signals (the classic solution from Transport Tycoon Original - download an example) and on the right is one using "one-way" signals (although a clover leaf is a more efficient design). One strategy that worked particularly well in Transport Tycoon Original was to have 'super highways' of track - up to 10 (or however many you want) parallel lines, with groups of "multiple slip switches" every twenty squares or so.

    Sure, it was good for the "two-way" signal system that was available at the time, but things have progressed since then. The major downfall of this design was that - like the crossovers - only one train could occupy the intersection at a time. So, instead of having the "slip switches" on neighbouring squares, why not separate them by one square and put a signal in the middle? That way two trains can effectively use the switch at the same time.

    The result is what I call a "signalled slip switch". (In the following sreenshots the trains travel from top left to bottom right). This arrangement proves to be quite effective when used on 'two lane' dual tracks (two tracks in each direction), and in certain situations at stations (which we'll look at shortly).

    If a train is already using the "slip switch", it is of no consequence because the signal in the middle of the intersection 'protects' the approaching wood train from what would normally be a red signal in the 'standard' "slip switch" (above).

    If the signal on the main line is red and the other line is clear, the wood train can simply switch lines. If the track ahead is blocked and there is another train using the switch, then it's no great loss as it's no different to having many trains on a single track.