Today, the highway's appearance implies only minimal maintenance, as does the jostling ride produced by the rough surface.
Today the way the highway looks shows that very little has been done to keep the road's surface in good condition. We also know that the road has not been cared for, because its uneven surface causes passengers to have an uncomfortable ride, bouncing up and down and sideways (jostling).
The shoulder of the road is the unpaved portion of the roadway at either side:
The car is parked on the right shoulder.
I hope this is helpful.
Student or Learner