Not having your license with you when driving
You're not going to be arrested if you do not have a license physically present and you have been pulled over on a routine check. However, it is a serious offense if you have been driving in full knowledge that you have had your license suspended, or with the knowledge that it has been made invalid in some other way.
What are the penalties that you could face?
Title 75 section 1501(a) of the motor vehicle code considers driving without a license to be a summary offense that may be cured by presentation of a valid driver's license to the magistrate issuing the citation within 15 days.
Title 75 1543(a) imposes a 1 year minimum suspension on a driver driving under a SUSPENDED license. Additionally, if the suspension was the result of a conviction or ARD for a DUI offense, driving under suspension carries a n automatic 60 DAY JAIL SENTENCE.