How it works
The mod Minecart is optimized for low server lags. The railway route is only calculated once by a minecart and then stored in railway blocks. In this process, the route is divided into segments. A segment is a piece of route without a change in direction. At the start of each segment, the moving direction and speed is stored in the railway block, represented by the black/yellow dot at the railway block.
This makes it possible for many cars to drive on the routes without putting a heavy load on the server.
The speed calculation is different to the default carts. For each section, the speed is calculated once from the length, number of power rails and slope. As a result, carts always have a constant speed in a section, or do not go through the section at all if, for example, power rails are missing. The maximum speed is 8 m/s. This assumes a ratio of "power rails" to "normal rails" of 1 to 4 on a flat section of route. The speed of the carts is mainly influenced by power rails. Brake rails are irrelevant, the cart does not brake here.
After every curve / kink, the speed for the next section of the route is newly determined, taking into account the swing of the cart. This means that a cart can roll over short rail sections without power rails.