This is a pre-signaled modified cloverleaf, with the possibility of U turns on special tracks. It's based on the Building depots which uses pre-signals to give priority to the trains on the main line. The exits from the mail line are before entrances, reducing traffic problems (Fig.1).
- Traffic jams less likely.
- Can handle a large number of trains at a time.
- Exits from main line are before entrances, reducing the chance of traffic problems.
- Very costly to build.
- Trains must slow down to climb a slope.
- Trains must slow down during sharp turns.
- Trains must turn left to turn right. This could lead to trains getting lost. (Can be fixed by using waypoints).