A traffic signal is a control device that assigns right of way among road users at an intersection or crossing.
Definition
A traffic signal controls the assignment of right of way among road users at an intersection or crossing. A civil engineering project involving a signal may include evaluating whether a signal is appropriate, preparing plans, specifying equipment, developing timing, coordinating utilities or communications, and obtaining agency review. Which tasks are included depends on the agreement, site conditions, and jurisdiction. Firms estimate effort based on the deliverables, data, coordination, and approval stages in scope. Operation and maintenance are typically assigned through the relevant road authority or contract. A signal is not simply a set of lights, and preparing engineering documents does not itself authorize installation or determine operating responsibilities. A project may require separate work for timing, equipment, power, and field implementation. For transportation program context, see FHWA.
How owners use it
- Owners define whether the assignment covers evaluation, design, timing, equipment, or agency coordination.
- A design review has 5 signal sheets and adds 2: 5 + 2 = 7 sheets to review.
- Project managers track power, communications, and approval interfaces as scope items.
- Owners distinguish signal design from signal operation and maintenance.
