76 is the Turnpike in that segment. You'll want the District 1 and District 2 Turnpike VHF repeaters which you can find in the database. For the portion of I-70 independent of the Turnpike it's patrolled by PSP and unless they come up on the old VHF you won't hear them since they're on the Open Scam (ahem Open Sky) system.
Local jurisdictions at least in western pa do not perform active enforcement on interstates. That usually falls under state police jurisdiction. Now if they happen upon they will stop and render assistance while waiting for PSP.