A traffic impact study (TIS) is a technical analysis assessing how proposed development will affect surrounding transportation networks, including traffic volumes, intersection operations, safety, and required improvements. Municipalities typically require traffic impact studies for developments above certain size thresholds or in sensitive locations. Studies project traffic generated by the development, analyze how existing infrastructure will accommodate increased traffic, and identify required improvements like turn lanes, traffic signals, or road widening. Study requirements specify methodologies, analysis periods, and required scenarios. Developers commission qualified traffic engineers to prepare studies, which municipalities review as part of development applications. Study recommendations may become conditions of development approval, with developers funding required improvements.