Talk to traffic engineers about their careers. Ask them what they like and dislike about their jobs and for advice on preparing for and landing a job in the field. If you're in college, join a student chapter of the Institute of Transportation Engineers to see if a career in transportation engineering is a good fit for you. 

Traffic engineers study factors such as signal timing, traffic flow, high-accident zones, lighting, road capacity, and entrances and exits in order to increase traffic safety and to improve the flow of traffic. In planning and creating their designs, engineers may observe such general traffic influences as the proximity of shopping malls, railroads, airports, or factories, and other factors that affect how well traffic moves. They apply standardized mathematical formulas to certain measurements in order to compute traffic signal duration and speed limits, and they prepare drawings showing the location of new signals or other traffic control devices. They may perform statistical studies of traffic conditions, flow, and volume, and they may—on the basis of such studies—recommend changes in traffic controls and regulations. Traffic engineers design improvement plans with the use of computers and through on-site investigation.

Traffic engineers address a variety of problems in their daily work. They may conduct studies and implement plans to reduce the number of accidents on a particularly dangerous section of highway. They might be asked to prepare traffic impact studies for new residential or industrial developments, implementing improvements to manage the increased flow of traffic. To do this, they may analyze and adjust the timing of traffic signals, suggest the widening of lanes, or recommend the introduction of bus or carpool lanes. In the performance of their duties, traffic engineers must be constantly aware of the effect their designs will have on nearby pedestrian traffic and on environmental concerns, such as air quality, noise pollution, and the presence of wetlands and other protected areas.

Traffic engineers use computers to monitor traffic flow onto highways and at intersections, to study frequent accident sites, to determine road and highway capacities, and to control and regulate the operation of traffic signals throughout entire cities. Computers allow traffic engineers to experiment with multiple design plans while monitoring cost, impact, and efficiency of a particular project.

Traffic engineers who work in government often design or oversee roads or entire public transportation systems. They might oversee the design, planning, and construction of new roads and highways or manage a system that controls the traffic signals by the use of a computer. Engineers frequently interact with a wide variety of people, from average citizens to business leaders and elected officials.

Traffic technicians assist traffic engineers. They collect data in the field by interviewing motorists at intersections where traffic is often congested or where an unusual number of accidents have occurred. They also use radar equipment or timing devices to determine the speed of passing vehicles at certain locations, and they use stopwatches to time traffic signals and other delays to traffic. Some traffic technicians may also have limited design duties.