Arteries have a generous supply of smooth muscle. It relaxes to allow more blood to flow to an area, and dilates to restrict the local blood flow.
Veins have less smooth muscle, but it is also of great importance.
It is the venous smooth muscle that gently pumps blood back to the heart. Except when the heart is failing, this is the way cardiac output is regulated. This is an artery. You have already learned to spot smooth muscle when it is present in large quantities. Seeing it around vessels is almost as easy.