HARRISBURG — Motorists who repeatedly blow through Pennsylvania Turnpike tollbooths without paying have until Friday night to pay up, in some cases at a reduced rate — or risk having the state suspend their vehicle registrations.

The Turnpike Commission announced its amnesty program last month, and in the first three weeks, 1,645 violators paid a combined $1.1 million in fines, it said. But about 8,900 violators still owe a combined $16 million, according to the commission.

"While it represents a fraction … it is revenue we didn't have a month ago," Turnpike chief operating officer Craig R. Shuey said in a statement Tuesday. "Equally as important, chronic toll violators now know what they must do to avoid possible suspension of their vehicle registrations."

A state law that goes into effect Friday will allow the Turnpike Commission to work with the state Department of Transportation and suspend registrations for drivers who repeatedly skip out on turnpike tolls. (Not only does it cost $91 to reinstate a registration, driving under a suspended registration is a summary offense that carries fines.) The deadline for participating in the amnesty program is 7 p.m.

While the program is targeted primarily at repeat offenders — those with six or more outstanding violations — anyone can participate.

The program allows people with violations that are less than 60 days old to pay just the outstanding tolls, and have the additional fees forgiven. The agency usually charges a $25 fee for the first notice of an unpaid toll and a $40 fee for the second.

Violations older than 60 days can be settled at a reduced fee amount. In some cases, the commission says, payment plans are available.

People who wish to participate in the amnesty program can call 1-877-PennPass (877-736-6727) and select option 2. That line works on weekdays from 8 a.m. to 7 p.m.

When it was pushing for the ability to suspend vehicle registrations, the Turnpike Commission listed its top two dozen commercial offenders, many of whom were from out of state. The new law allows Pennsylvania to set up reciprocal agreements with other states to allow them to crack down on one another's violators, but those agreements haven't been finalized.