I really don't know whether you found that the trail was covered with pebbles when you're on the train. Do you understand what these pebbles do?
So why do you have to put so many pebbles?
It turns out that these tiny stones are utilized to carry the roadbed, disperse the weight of the trains and railings, can cushion the shock absorption, and decrease the deformation of these rails, etc., and have lots of advantages.
So as there are many advantages in laying a street, why's there no high-speed Rail?
When the train rate is too high, those pebbles will occasionally roll down.
And therefore don't worry, what exactly does the high-speed rail usage?
The high-speed rail is directly poured into the cement railing, which not only reduces maintenance but also reduces the rate of the dust.