Going Green by Flashing Yellow

Worldwide, there is growing recognition and concern surrounding the impacts of human activity on the planet’s ecosystem. A broad spectrum of interests including political leaders, scientists, environmental experts, and individuals are seeking to reduce sources of global warming, and the transportation engineering/planning industry is being called to contribute solutions.

Providing increased efficiencies within existing pavement is a challenge facing many agencies who are at the same time working with constrained budgets. Efficient operation of traffic signals is an area where driver delay and emissions benefits can be realized. Relatively straight-forward activities such as optimizing traffic signal timing and choosing appropriate phasing can be made at both existing and new traffic signals to minimize delay and, in doing so, reduce emissions.

Now a part of the MUTCD, the Flashing Yellow Arrow protected/permissive left-turn (FYA PPLT) signal display is a relatively new traffic control device in the transportation engineering professions’ toolbox. The safety and operational benefits of the FYA display are well documented and the public reception has almost universally been positive. Agencies implementing FYA PPLT control are benefiting from both delay and emissions reductions.

Use of the Flashing Yellow Arrow (FYA) at signalized intersections is a low-cost approach to reducing delay and greenhouse gas emissions. This presentation highlights benefits and limitations, and agency-based lessons learned in the use of FYA protected-permissive left-turn (PPLT) signal control. An overview of the FYA PPLT control is presented along with key implementation factors for both design and operations. A few case studies on the implementation of FYA PPLT control throughout the nation would be presented. This information should be of particular interest to agencies exploring use of FYA PPLT control.

Session attendees can expect to learn about:

• The difference between Flashing Yellow Arrow (FYA) & green ball indications, as well as design considerations;

• What is the yellow trap and how it can be addressed through FYA?

• Operational and safety benefits, trade-offs, and lessons learned of FYA left-turns;

• Videos and case studies on various applications of FYA;

• An extended period for group discussion…come get your questions answered!

Sponsored by the Miami-Dade County, all public agency staff from the region are encouraged and welcome to join in this session.

About the Speakers

Shaun Quayle, PE Senior Engineer, Kittelson & Associates, Inc., Portland, Oregon
Shaun is a senior engineer with Kittelson and Associates, Inc., who has over 10 years of experience in traffic signal systems, design, and traffic operations. His experiences include signal timing optimization projects in numerous states, including advanced signal applications such as gap-dependent FYA settings, co-development of custom FYA-ped friendly logic, and numerous FYA implementations and evaluations. He is involved in the FYA sub-committee in the State of Oregon, and assisted the sub-committee in developing advanced FYA applications.

Shing Tsoi, PE Engineer, Kittelson & Associates, Inc., Fort Lauderdale, Florida
Shing is an engineer with Kittelson and Associates, Inc., who has 4 years of experience in traffic engineering. He is actively involved in projects related to traffic signal systems and traffic operations. His experiences include signal timing optimization projects, transit signal priority and other signal operations and safety studies in various states. He has explored and has understanding on various types of traffic signal controllers on their capabilities of implementing FYA operations.

Event Materials