Signal Aspects This is an overview of how the default signalling system that comes with Zora no Densha works. Main Signal Aspect Distant Signal Aspect Indication Meaning   STOP Stop before the signal - passing is not permitted. CAUTION Proceed at normal speed. Expect the next signal to be displaying STOP . EXPECT SLOW Proceed at normal speed, prepared to do 40 km/h at the next signal. CLEAR Proceed at normal speed. Expect the next signal to be at worst a CAUTION . HIGH SPEED Proceed at normal speed. At least 3 blocks ahead are unoccupied. The next signal is at worst a CLEAR or EXPECT SLOW   CLEAR SLOW Proceed at 40 km/h, unless indicated otherwise. The next signal will be displaying a proceed indication, at worst a CAUTION .   CAUTION SLOW Proceed at 40 km/h (unless indicated otherwise). Expect the next signal to be displaying STOP .   SUSTAINED SLOW Proceed at 40 km/h (unless indicated otherwise), prepared to do 40 km/h at the next signal.