Always, always, always call the locator service! It costs nothing to do so. If you don't, and hit something... the costs of repairs to utility is on you or your next of kin. If the locator service fails on their end... it's on them, not you.
i hear NJ horror stories all the time
a contractor friend was threatened with arrest after hitting a gas line
state police were very nasty, until they investigated & realized his company HAD CALLED and the area was marked but the location service MISSED BY 92 FEET