The answer to that question is somewhat complicated. It makes sense to first talk about what happens to your normal (passenger vehicle) license in this situation (where you have been arrested for a DUI and you refuse the officer's request for blood or a breath test). When you have been arrested for a DUI and you refuse a blood, breath, or urine test your license gets suspended for one year (so long as the officer took your license and submitted what's called a "Form 1205" to the DDS). You would have been given a copy of this Form 1205 by the officer. Here's the weird part -- the Form 1205 tells you that you can get your license back in two ways: (1) doing an ALS appeal within 30 days; or (2) getting an Ignition Interlock driving permit (having an interlock device installed on your vehicle and going to DDs for the ignition interlock driving permit).
However -- if you do option #2 (and you have a CDL) If a Commercial Driver's License (CDL) holder, the issuance of an IIDLP will automatically downgrade the CDL temporarily, with no commercial driving privileges throughout the duration of the suspension. That means if you get an IIDLP you will lose your CDL for at least 12 months! In other words, DON'T DO THIS!
Call us at (770) 249-4405 to discuss your options asap.
Read more about your rights in the context of a Refusal to provide a breath/blood test here.