John ThomasTraffic Safety, Traffic Signals

When you think about short-term temporary traffic control, what solutions come to mind? Today there are several options are available, including flaggers, automated flagger assistance devices (AFADs) and portable traffic signals. Choosing the best option for your work zone depends on variables such project duration, location of work, road type, geometrics, intersections, road user volumes, travel speeds and other factors. Below is a summary of the different options and guidelines for considering each short-term temporary traffic control option for your work zone.


Flaggers are commonly used for traffic control in work zones in applications where one lane is closed on a two-lane road.  MUTCD guidelines for flaggers are documented in Section 6E.01, which states:

Because flaggers are responsible for public safety and make the greatest number of contacts with the public of all highway workers, they should be trained in safe traffic control practices and public contact techniques.

Flaggers have one of the most dangerous jobs in the work zone because they stand directly in the line of traffic. Several flaggers are injured or killed each year from distracted and errant drivers. Flaggers typically wear reflective clothing and use a STOP/SLOW paddle to direct traffic. Finding qualified, well-trained flaggers is often a challenge – especially during peak construction seasons. In addition, flaggers are human and can easily become fatigued or distracted on the job, putting them at greater risk. When they call in sick unexpectedly, it can be a challenge to find a qualified (trained) replacement on short notice.

Automated Flagger Assistance Devices (AFAD)

Automated Flagger Assistance Devices help control traffic in a work zone – without replacing flaggers. The trained flagger stands safely off on the shoulder and can operate the AFAD using a radio remote control. Depending on visibility within the work zone, one flagger can operate one or two AFADs to control traffic. AFADs come in two forms: the most basic has a STOP/SLOW paddle design and the other has an illuminated Red/Yellow signal lens. AFADs have a reflective gate arm to provide a physical barrier to prevent motorists from entering the work zone. The illuminated Red/Yellow lens AFADs are typically more visible than flaggers for short-term traffic control. AFADs like the Sentinel AFAD by JTI are designed to be easily towed or wheeled away at the end of each workday.

Portable Traffic Signals (PTS)

Portable Traffic Signals, like JTI’s ADDCO PTS-2000 provide an alternative to flagging and provide the optimal traffic control safety solution for work zones. PTS are typically trailer-mounted and can be towed to the site and setup in minutes.  Other compact models of PTS are available for tight work zones or shorter-term operations, including the Sentinel PTS by JTI which is available on a towable trailer or a wheeled base that is easy to push/move even on gravel.

Portable traffic signals provide many advantages. They are recognizable by motorists who are already familiar with permanent signals – increasing compliance. PTS can provide 24/7 traffic control in the work zone and never get fatigued. They are stand-alone with batteries and solar recharging, requiring minimal maintenance. PTS free flaggers to work on other duties within the work zone. JTI offers a complete line of portable traffic signals for every application.

Specialty Portable Traffic Signals

Every work zone is different, often requiring a portable traffic signal network to control traffic. For example, often there are driveways and side streets that must be synchronized within a one-way travel path through the work zone. Systems like JTI’s Sentinel DAD (driveway assistance device) are designed specifically to control work zone traffic entering the traffic flow from driveways and side streets. These systems can be integrated into a complete temporary traffic control signalization plan. Contact JTI for details.