Advance warning signs alert you to an upcoming crossing, and tell you to look, listen and slow down because you may have to stop. They are usually posted in locations where you cannot see an upcoming railway crossing (for example, on hilly or curvy roads). An advisory speed sign below the advance warning sign may show that the safe road speed is less than the posted speed. You may see a painted “X” on the pavement at the approach to some railway crossings. Some crossings also have flashing lights, a bell and gates. If the light and bell are activated or the gate is down, it means a train is approaching.