Street Lighting and Traffic Controls
Ontario Regulation 213/91: Construction Projects states the following about precautions to be done before excavation:
the employer excavating shall ensure that all gas, electrical and other services in and near the area to be excavated are located and marked.
Traffic lights help keep traffic on roads moving as freely and smoothly as possible. Traffic lights and street lighting lines are major hydro lines and are usually buried underground and across parking lots, roads, neighborhoods, etc. The best way to eliminate this risk is to request a utility line locate before you commence your work. This will give you the clearance you need to have before starting any digging in the intended area of construction. And as the old saying goes, CALL BEFORE YOU DIG!