as you encouraged me liking my playing around with pp in WS, I did it once again to keep up the fun.....

In your photo I felt that your man didn't had enough space to demonstrate his speed blocked a bit by the limitetion of your left black border as he would smack into a wall ....
so
no borders of limitation anymore
and
I gave him some more space by pulling out the space left to him , possible as it was already blured and I left the declining perspectif without the curb at the end to open up that by itself the speed would increase by going downwards.
OK
on top I have put a gradiant shade to the left and the right of your main actor and I added slightly some more colored lines at the edge on the left by a top layer saturation 100% up and erase + smudge in horizontal lines reducing opacity so that you can feel it but not notice it so much.
Fun ?