How to Prove I Wasn't Given a Speedy Trial

My question involves traffic court in the State of: Missouri

I got a traffic ticket and mailed in my non-guilty plea. It's been over a month and I still haven't received a court date. Supposing I eventually get a date that's more than 70 days after they received my plea, what steps should I take now to make sure I can prove that I wasn't given a speedy trial? Is there any way I can get a verification from the DA's office that they received my plea? I already called them and they said they have it, but haven't sent it to the courthouse yet.

This is important because I'm planning to move to another state in August. If I don't get a trial date that's before my move, perhaps the judge will accept a motion to dismiss.

Thank you kindly in advance for your help!

You have to specifically state you are ready for trial and demand a prompt date, otherwise they're not obliged to make any haste in the scheduling. If you do make such a demand and they don't respond promptly, you can move (though it's at the discretion of the judge) to dismiss the case.

Okay, thank you.

Is there any specific procedure for demanding a prompt date? Do I ask the courthouse or the district attorneCan it be made over email? If I mail a letter, won't they be able to claim they never received it?