Unnecessary under most circumstances.

If you're planning to fight it, do it on your own. You're essentially betting whether the cop shows up or not. If he does, you probably lose no matter who is representing you. If he doesn't you probably win.

I am not saying it wouldn't be useful if you were really innocent, but if you have a speeding ticket and your driving record is so poor that you can't suck it up, slow down. Just the cost to retain the lawyer would likely be more than the ticket.

Became necessary to avoid gaining points on my license and watching insurance increase.