When driving long straight routes hour after hour, drivers may experience a state of inattention known as

The given blank can be filled with highway hypnosis.  

Highway hypnosis is possibly best illustrated as the partial inattentiveness and a distinction between the unconscious and conscious reactions of the body and brain. In the condition, the individuals are not asleep, but they are not fully attentive or conscious either. It signifies that the individuals are not completely and consciously involved in the act of driving the vehicle.  

weathering - colorado river carves land in arizona to form the grand canyon. cracks form in a sandstone wall surrounding a house. a marble statue near the science museum is changing color due to rainfall

erosion - after a rainstorm, soil and rock piees litter the roadways. the sand dunes in the sahara desert are changing shape.

here's your answer.