The County Planning Commission may make or cause to be made and laid before the said county commissioners and, in its discretion, cause to be published, a map or maps of the county and any portion or portions thereof, including the territory extending three miles beyond the county limits, showing the highways and other public improvements hereinbefore specified and other natural or artificial features, and also locations proposed by it for any new highways or other of such improvements, or any widening, extension or relocation of the same, or any change in the county plan by it deemed advisable.
16 P.S. § 5205