Can a stop sign controlled intersection be replaced with a traffic signal?
Like stop signs, traffic signals are used to assign vehicular and pedestrian right-of-way. They are typically installed on higher volume roadways and are used to promote the orderly movement of vehicular and pedestrian traffic and to prevent excessive delay to traffic. Traffic signals cannot be installed unless one or more of the warrants specified by the Manual on Uniform Traffic Control Devices (MUTCD) has been satisfied.
See this FHWA Safety Brief (https://safety.fhwa.dot.gov/intersection/other_topics/fhwasa10005/brief_5.cfm) to learn more about the purpose of traffic signals, where they should / should not be installed, and advantages / disadvantages.
You may also visit the Transportation & Engineering Traffic Signal webpage (https://www.jeffco.us/3981/Traffic-Signals).