Is it a copyright infringement to make a map based on another map?

I want to make a vector based map of a city for business purposes, and maybe even to sell. Is it a copyright infringement to use another map (importing a pdf of said map into illustrator to find locations of roads and places, and then basically tracing over it on a new layer. in the end deleting the pdf of the old map) to create my own map with a different visual style. My new map will have different line weights colors, ext from the original. The map I want to use is from a county government gis map.