According to USDOT Solicitation Notice DTRT5714SS00007 that is posted on FedBizOpps (https://www.fbo.gov/index?s=opportunity&mode=form&id=2df765acc2f0788ae1bc40ff0d70fe30&tab=core&_cview=0)
The Notice says "While ALPRs are deployed for a variety of purposes (i.e., homeland security, locating and recovering stolen vehicles, etc.), the purpose of this study is to focus on the use of ALPRs for traffic safety purposes. Within traffic safety, the emphasis will be on license offenses, including revoked, suspended, or restricted licenses; however, the study should reveal whether ALPRs are being used for any other type of traffic safety function (e.g., speed enforcement).""
Link to Original Source