Railcraft Mod 1.12.2/1.10.2/1.7.10 began as a simple mod. However, it now contains a full tech tree with a series of features about player transport such as tracks, carts.

Much more about Railcraft
The owner has turned it into an ideal release. It actually balances the gameplay.
It’s also one of the pioneer mods about multi-block structures. It has a load of these constructions like the strong steam Boiler or the massive Iron Tanks.
Main features
General
Crowbar – quickly adjust the rail for skilled engineers
Working Signalling System – prevent head-on collisions
Cart Linking & Locomotives – form a real train
Multi-block structures – for when the magic block doesn’t cut it
Tracks
Boarding and Holding Rails – unnecessary to chase your minecart anymore
One Way Rail – carts will go the right way
Control Rail – easy to propel carts
Junction Rail – place the diamond in rails
Launch Rail
High Speed Rails
Reinforced Tracks – for other nether railways
Wooden Rails – only with creepers
Elevator Rail – move up rapidly
…
Carts
Steam Locomotive – travel all the time
TNT Cart – create fun explosions
Tank Cart – fast to deliver Buildcraft liquids
Energy Cart – can bring your IndustrialCraft2 power
Tunnel Bore
Blocks
Detector Blocks
Loader/Unloader
Cart Dispenser
Iron Tanks
Steam Boiler
World Anchors
Besides, there are numerous bug fixes. Moreover, you are able to configure various stuff.
Railcraft is a technology mod that mentions plenty of issues in the game. It requires you to install Minecraft Forge.
Screenshots