Bored at work watching the excavators ripping sandstone to bits. How far can you see around corners? That was the question asked by our HART instructor. What he was getting to was how fast can you go around bends etc We have all sped past the yellow speed advisory signs and scoffed at how slow the intended speed is. Our HART instructor was the first person to ever explain these speeds to me and he said "if you travel around the bend at the advised speed, you will have 5 seconds of reaction time available" So as we all zoom around these corners faster than the recommended speed, we are accepting a shorter reaction time/space for an emergency situation than the 5 second stop. Say we come around a blind corner to a totally blocked road, do we have enough time and space to set up, stand up and brake? Do we all just accept that risk, or trust our evasive skills if needed?