What can I do to make this look better and more realistic?
Add some street lights! I can’t quite see the whole picture. But otherwise, it looks realistic!
Bars between the two sides of the motorway.
I would also recommend streetlights to add more depth to the game.
from everyone’s answers, it is correct to add lights,
Recommended to add the functional street lights along the street.
It looks like the road ends here, maybe add fog something to slightly darken the area up. Hope this helps.

As others have said, definitely street lights.
Other than that, I am unsure what you are going for but more background scenery could look good such as city buildings in the far distance or tall trees maybe. Also, the wall seen on the right side of the image could just use added detail, I don’t know what it is meant to be but adding a trim to it as well as a texture could go a long way.
Looks a lot better, I’d still add more to that wall on the right.
mb for the late reply but

Also, try adding future lighting, it will make the build better 100%

