This chapter shall not be construed to relieve or lessen the responsibility of any person owning or operating or installing any sign for damages to property or injuries to persons caused by the construction, maintenance or operation of any sign or any defect therein, nor shall the city or any agent thereof be held or construed as assuming any such liability or responsibility by reason of the permits, fees and inspections provided for in this chapter. The minimum safety requirements and regulations prescribed in this chapter shall not relieve the property owner nor the person constructing or maintaining a sign from the obligation of taking any additional steps necessary to make and keep the sign safe for persons and property. The city and other public agencies are not responsible for damage caused to signs overhanging the public right-of-way during maintenance operations or construction activities.