[vc_row][vc_column width=”1/1″][vc_column_text]By Ed Murphy
Our guest speaker at our regular lunch meeting on April 9th was Chris Brehmer, a Principal Engineer with Kittelson & Associates Inc. Chris’s program was about creating and advancing a new left-turn signal – the flashing yellow arrow. Chris has assisted with a variety of transportation engineering and planning projects in his 18 years with the firm. He served on a team of engineers that investigated different types of protected/permissive left-turn signal displays as part of a national research project that culminated in development of the flashing yellow arrow left-turn signal. He presented an overview of the research project, creation of the flashing yellow arrow, and some of the current advances/refinements in flashing yellow arrow implementation.
For some background, Chris talked about the history of the flashing yellow arrow, which is a permitted left turn, after yielding to oncoming traffic. He said that, back in 1995, the Manual on Uniform Traffic Control Devices (MUTCD), published by the Federal Highway Administration (FHWA) was pretty vague, and many states and regions had their own versions of such turning movements. Kittelson & Associates led a research project from 1995-2004 that evaluated the safety and effectiveness of different signal displays. The research involved conducting surveys of drivers, carrying out operations studies, performing conflict studies, analyzing crash data, etc. After reviewing all the various practices used at that time, they came up with a “none-of-the-above” solution – the yellow, flashing arrow, or FYA. It hadn’t been tried anywhere before.
To introduce this new method of traffic control and get approval for its widespread use, they had to conduct full scale driver simulations, and also deploy the signals at 6 places around the country. With this testing, they documented that the FYA performed better than the alternatives. In 2003, they issued their final report. But they still had a long ways to go. In 2006, the FHWA allowed the use, but with restrictions that dampened the interest of cities and counties. But with more testing and follow up studies, the FHWA finally allowed the use of the FYA, without any restrictions, in 2009.
Oregon was an early adapter, with initial sites set up in Medford and Beaverton. Chris said that it worked so well that people started asking for them. In 2009, Washington County used some of its stimulus money to place them at 174 different locations – the largest deployment in the United States. They were so popular that the County staff started receiving complimentary mail – something quite unusual! Chris reported that the County saw a 20-40% decrease in crashes compared to other methods. They found that motorist confusion was reduced, and moreover, that drivers understood what they were supposed to do without supplementary signage. Newer technology now allows the County to balance mobility and safety by fine-turning the FYA to, for instance, change when and for how long the arrow flashes, adjusting it as needed by time of day, detection of gaps in traffic, or pedestrians using the crosswalk.
For more information on the Flashing Yellow Arrow and to watch a 3-minute video, please visit http://www.co.washington.or.us/LUT/TrafficSafety/DrivingSafety/flashing-yellow-arrows.cfm.[/vc_column_text][/vc_column][/vc_row]