Consider the following provisions regarding safety on highways, where major improvement works may also be in progress: 
1) Highly visible barricades to avoid falling of vehicles in deep interspaces ahead (including drainages). 
2) Wire-net provisions to ward off road slippages. 
3) Signages for wild-animals crossing (like deer, elephant, etc.). 
4) Signages on minor gradients. 
Which of the above are relevant?