Whenever in the opinion of the city council the public interest or convenience may require, that body may:

The improvement shall be for a period to commence at a time to be fixed by the city council but not exceeding five years from the date of commencement thereof.

The provisions of this part shall not be limited to the improvement of street lighting systems owned only by the city, but the city council may also order such improvement to be made upon street lighting systems provided and installed by, and remaining the property of, any public utility, public corporation, or other person with whom a contract is entered into for such improvement and may assess the costs and expenses thereof in accordance with this part.

If there is more than one street lighting system in any city any or all of such systems may be consolidated and improved under one proceeding. In such case the consolidated system shall be zoned so that those systems of approximately the same general type are grouped together.

Whenever a street lighting system is installed along a boundary line or street of any city, the city council may, by resolution, assess the land abutting upon such boundary line or street for the estimated cost and expense of improving the system, even though the system is partially or entirely without the boundaries of the city.

If land has been assessed pursuant to Section 18324, the city council may proceed in all respects in connection therewith as though the street lighting system were entirely within the city limits; except that the city council may enter into a contract with the legislative body of the city or county having jurisdiction over the adjoining territory either to improve all or any portion of the street lighting system, or to have all or any portion of the system improved by the legislative body of the adjoining territory. The legislative body contracting to furnish such improvement may enter into any contract or issue any purchase order authorized in this part.