Basically the title. I’m curious what they do to decide. surely they don’t just stick a random number on a sign and call it a day.
In: 16
My turn! When a road is being designed they have to consider how the road curves either from changing elevation, switchback roads, or both. IIRC the speed limit is generally determined by how fast an object of X mass(the cars) can safely make the turn in best weather scenarios. Safely meaning you can make the turn at a certain speed without losing traction and driving off the road or still have time to slow down some in case of emergencies.
Most designs are also made with nighttime considerations so when your headlights are on and driving around those road curves we don’t blind each other. (Why it’s not legal to tamper with your headlights.) Good design practice should also drop the driving speed limit from the design speed limit to accounting for bad weather conditions. This still doesn’t say anything about road width, city/school zones, straightaways, etc. Initially we did not care so much about making roads but after the first decade of automobile accidents it was apparent changes needed to be made.
Latest Answers