The use of the blur filter in Photoshop can be an effective tool in eliminating distraction while at the same time impressing an abstract effect on your photo. The effect is also applied to isolate a subject or draw attention to a part of a picture. Radial blur can be most effective when your subject is in the center of your image like the two cars shown in my example. The simplest way of achieving this effect are as follows: open your image in photoshop, zoom in to have a larger workspace. select the subject using the polygonal lasso tool or any selection tool. inverse your selection, feather your selection to at least 5 pixels if you're working on a large image, apply the blur, which may either be the spin blur or the zoom blur, and that's about it.
The yellow car above is an example of a zoom blur while the red car below made use of the spin blur to suggest a spinning motion or a vertigo effect. If used on the moving car or any subject in motion, the radial blur can also be an effective way of dramatizing speed.