Bridges

For the ship equivalent, see Aqueducts. Bridges are a commonly used infrastructure in the game. Bridges can help shorten the time it takes to move a transport to its destination by avoiding slopes and water. There are two types of bridges, road and rail bridges. They also can let ships travel under them (if they're over water) or other roads and tracks pass under. Bridges also solve the problem of going over competitor owned tracks and roads.

Requirements
In order to be built, the area the bridge is crossing must have the following:


 * Flat land or over land sloped towards the bridge (no diagonal slopes underneath)
 * Above regular (full) water tiles
 * Starting and ending at different heights (no more than 1 level), i.e. the starting/ending tile is on a sloped surface while the other end is on a flat surface

These two only apply if the "New Bridges" patch is not enabled:


 * Above regular and unmodified rail/road/canal tiles (same goes for constructing those under a bridge) (i.e. you can't put signals under bridges)
 * Above diagonal tracks

To build a bridge, go to the build bridge tool, and click on the tile where you want to start the bridge. Drag until you reach the desired length and release. Select the bridge type you want. Now you have a bridge!

When building bridges over uneven land, make sure the land under the bridge is sloped towards the direction of the bridge, otherwise the bridge can't be built. You can also build bridges that vary in height by one tile, which may help in stations.

Strategies and Tips
Bridges should be not build in random spots, as it will slow faster vehicles down with its speed limit.

They should be built:


 * Over bodies of water, such as inland lakes and shorelines
 * Rivers, although you could just destroy the tile
 * Over other types of transport lines (e.g. a train bridge going over a canal)
 * Avoiding crossings with lines that have high traffic (of same type or not)
 * Strategic placement with stations or junctions
 * Moving across valleys without having to go all the way to the bottom

When building bridges over extremely long stretches (for whatever reason), you might want to consider making mounds to continue the bridge. The game won't let you build bridges over a certain number of tiles (around 80 tiles, this can be changed in settings), and building mounds may help you continue the bridge. To build, you may need to build markers to keep the alignment right. When at the designated point, draw a 0*1 line using raise land in the landscaping tools. You will now have a slope to build your bridges! if you extend it to 1*1, you will make a bigger mound, allowing for multiple bridges to be connecter, or have a turn on to a bridge going in a different direction.

Pros

 * Allows the crossing over water and other roads/tracks
 * There are more options and looks using NewGRFs
 * Useful when crossing tall and/or wide valleys

Cons

 * May be expensive, especially over long distances
 * Can't cross over stations, buildings or airports
 * Speed limit may hinder later vehicle

More Information
Types of Bridges