If you've driven under one of the new Mass. Pike all-electronic tolling gantries in the past month you may have noticed a camera flash as you approached.

Yes, it's taking a photo of your vehicle.

MassDOT confirms the new all-electronic tolling system has entered the testing phase and that cameras mounted to the gantries are taking photos of vehicles as they pass underneath. The system will continue to be tested throughout the summer, but motorists are not being charged as they drive under the gantries.

The new system, still set to launch in October, scans for EZ-Pass transponders and takes photos of license plates. Once activated, the new system will charge each vehicle with an EZ-Pass account a flat fee for each gantry you pass under. For vehicles without transponders, a photo taken of the license plate will be matched up with the registered owner of the vehicle, who will then receive a bill for the toll. The Pike's current toll booths at all exits and on-ramps will be removed.

Toll rates have not yet been set, but according to MassDOT will be revenue neutral -- meaning the cost of driving from one end of the state to the other will be about the same as it is now.

As part of the testing phase going on now, MassDOT says images are being captured and evaluated in order to fine tune the cameras and triggers as well as to train the system's optical character recognition.

Responding to request from MassLive about how camera images are being used and stored during testing, MassDOT replied in a written statement that sample images are being uploaded to a secure database and being discarded after they are evaluated.