Under the Pennsylvania Vehicle Code, DUIs are graded as first, second, or third or subsequent offenses based on a ten year look back period. Therefore, one could get their first DUI in 2000, and eleven years later get a DUI in 2011, and the second DUI would be graded as a "first offense DUI" for purposes of sentence and driver's license suspense. Section 3802 to 3804 of the Vehicle Code dictates said sentence and suspension.
However, Commercial Driver's Licenses ("CDL") are not treated the same way as Driver's Licenses are under the vehicle code in regard to DUIs. Section 1611 of the vehicle code dictates that any second offense DUI triggers a lifetime CDL revocation, BUT THERE IS NO LOOK BACK PERIOD. Therefore, one could get a DUI 20 years ago, and get another DUI that would be treated as a "first offense" for regular driver's license suspension, but would be at the same time treated as a second offense for CDL purposes and result in lifetime CDL revocation.
As such it is imperative if you have a CDL and get a DUI to contact an experienced DUI attorney. If you have a CDL and got a DUI call my office immediately.