Is it good to sit in the ancestral grave and have an expressway facing south?

There is an east-west expressway in the south, which doesn't affect anything! Now roads extend in all directions, and there are roads near many graves! This is normal. Ordinary.

This doesn't mean that what you said about tomb feng shui is good.

Need to know the details of all directions in the vicinity in order to analyze and judge.

For example, there are other graves nearby, which can also be described in this way. But the feng shui of the graves next to them is different.