The Westfield Police Department Traffic Bureau is comprised of one supervisor and two patrolmen. Officers have specialized training that enables them to conduct the investigation of serious motor vehicle crashes, plan the safe and efficient running of special events, and oversee the enforcement of commercial vehicle laws. The unit is also charged with the maintenance of the department's vehicle fleet and new-vehicle purchases.

The traffic unit investigates motor vehicle complaints and develops strategies to address those complaints. These strategies help to ensure the safety and well-being of the motoring public by reducing injuries, deaths, and economic loss that result from crashes. The unit is also involved with new and ongoing construction projects, promoting safety, and effective traffic control. The city's school crossing guards are also under the direction of the traffic unit.