actually a practical strategy?

Well, there's actually a way to generate permanent creep and therefore create the Highway of Creep.

Queens can use their Creep Tumor ability to cover the ground in creep at the cost of 25 energy.
The creep generated by a Creep Tumor is permanent and you can obviously place another Creep Tumor on the edge of the newly created creep.

There you go, you have your Highway of Creep, please drive safely and look out for the Zerglings!

They currently cost 25 energy and they are casted by the Queen.

The range of a Creep Tumor is comparable to SC1’s Creep Colony radius. They’re spawned just like buildings, they also have a rather short building time (15 secs) .

The Queen places a Creep Tumor and then she can move freely (or place another Creep Tumor). Once the Creep Tumor is ready it starts spawning creep.

No cooldown as long as you have the required 25 energy, no minerals needed.

You can kill the Creep Tumor and then the creep will start to fade away normally.

You can place a Creep Tumor only on existing creep.

The Creep Tumor is burrowed and has very few HP.