Yahweh is emphatic and urgent that a clear and level road be available for the people to return to him and free of obstacles to worshiping Yahweh. This echoes [Isaiah 40:3](../40/03.md). (See: [[rc://en/ta/man/translate/figs-metaphor]])
The words "high" and "elevated" have basically the same meaning here and emphasize Yahweh being exalted. See how you translated this in [Isaiah 6:1](../06/01.md) and [Isaiah 33:10](../33/10.md). See how you translated a similar phrase in [Isaiah 52:13](../52/13.md).
These two phrases mean basically the same thing and emphasize that Yahweh will strengthen and encourage those who humble themselves before him. (See: [[rc://en/ta/man/translate/figs-parallelism]])