The least control is the best control!
Engineers seek to use the least obtrusive measure that will work. Traffic signals usually are appropriate only after other measures are found to be ineffective in improving an intersection's operation.
If a Traffic Signal is Justified, What Will Happen Next?
Making it all happen.
If the study shows that less restrictive measures are not effective and a traffic signal is justified, engineers begin the numerous tasks in planning for, designing, and installing the signal equipment. Additionally, many new signals require other physical changes to be made to the intersection, along with new traffic signs and pavement markings necessary for the intersection to operate properly.
The time-line and cost.
Because of its complexity, a signal installation requires time and money to plan, design, and construct. A new installation on a major road typically costs about $75,000 or more. Timewise, the process, from an initial inquiry until the signal is operational, usually takes nine months to a year. Costs and time requirements are greater if the intersection is complex, the signal is to be interconnected to nearby signals, or special features or roadway changes are needed
At the intersection of two or more state highways or a state highway with a municipal street, the State pays the full cost of a traffic signal, including the on-going power and maintenance costs. Where a state road intersect a county road, installation and operating costs are shared by the State and the county, generally based on the number of legs of the intersection that are on the respective road systems. Costs for a signal at intersections of local roads and streets are the responsibility of the local jurisdiction. Residential and commercial land developers pay the installation and power costs for signal installations at intersections involving their access roads.
Ultimately, those who use our highways largely pay for traffic signals through the various user taxes. What would be most unfortunate is for our citizens to pay for an unjustified signal through taxes and pay again through unnecessary delays and increased accidents.