It might refer to vehicles being parked on the pavement. Perhaps vehicles drive onto the pavement to pass some obstacle. It may refer to hawkers trying to sell their goods or set up stalls on the pavement. Generally, something is on the pavement which should not be there.

Hi Rushabh, I believe "pavement encroachment" refers to driveways. For example, if your neighbor's driveway crosses the property line (onto your property), this would be an example of pavement encroachment.