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Flashing Yellow ArrowFlashing Yellow Arrow
Jerry KotzenmacherJerry Kotzenmacher
Minnesota Department of Minnesota Department of TransportationTransportation
Left Turns at Traffic SignalsLeft Turns at Traffic Signals
Three types of left turnsThree types of left turns PermissivePermissive Protected/PermissiveProtected/Permissive Protected onlyProtected only
Left Turns at Traffic SignalsLeft Turns at Traffic Signals
Permissive Left TurnPermissive Left Turn Least restrictiveLeast restrictive Low speedsLow speeds Low volumesLow volumes 3 section he3 section headad
Left Turns at Traffic SignalsLeft Turns at Traffic Signals Protected/Permissive Left TurnProtected/Permissive Left Turn
Protected with Green ArrowProtected with Green Arrow Permissive with Green BallPermissive with Green Ball Speeds Under 45mphSpeeds Under 45mph Low VolumesLow Volumes 5 Section Head5 Section Head
Left Turns at Traffic SignalsLeft Turns at Traffic Signals
Protected Only Left TurnProtected Only Left Turn Most Restrictive – MUST WAITMost Restrictive – MUST WAIT Safest Safest Speeds Over 45mphSpeeds Over 45mph High Volumes High Volumes
Left Turns at Traffic SignalsLeft Turns at Traffic Signals
Three types of left turnsThree types of left turns PermissivePermissive Protected/PermissiveProtected/Permissive Protected onlyProtected only
Guidelines for Type of Left TurnGuidelines for Type of Left TurnSpeed Speed
VolumesVolumes
Sight DistanceSight Distance
Opposing left Turn OffsetOpposing left Turn Offset
When guidelines call for protectedWhen guidelines call for protected
turn only - Options limited turn only - Options limited
Flashing Yellow ArrowFlashing Yellow Arrow Protected left turn head using Protected left turn head using
addition yellow flashing arrowaddition yellow flashing arrow
Can Operate Protected or Can Operate Protected or Protected/PermissiveProtected/Permissive
Time of day options.Time of day options.
Protected only turns benefit Protected only turns benefit most.most.
MN/DOT’s Pilot ProjectMN/DOT’s Pilot Project
Traffic signal located at TH 110 Traffic signal located at TH 110 & TH 149& TH 149
Test EquipmentTest Equipment FHWA approved interim useFHWA approved interim use Removed due to operation Removed due to operation
condition with yellow condition with yellow clearance.clearance.
Successfully operated for 3 Successfully operated for 3 yearsyears
Why?Why?
Continual public dissatisfaction with Continual public dissatisfaction with “protected only” signal phasing “protected only” signal phasing
North Central Section Institute of Traffic North Central Section Institute of Traffic Engineers (NCITE) supported Engineers (NCITE) supported
Improved signal operationsImproved signal operations
Why?Why?
NCHRP Report 493 concluded that:NCHRP Report 493 concluded that: (National Cooperative Highway Research Program)(National Cooperative Highway Research Program)
The FYA was found to be the best overall The FYA was found to be the best overall alternative to the circular green alternative to the circular green
FYA was found to have a high level of FYA was found to have a high level of understanding understanding
The FYA display in a separate signal face for The FYA display in a separate signal face for the left-turn movement offers more versatility the left-turn movement offers more versatility
Operation NotesOperation Notes
Red time after green/yellow arrowRed time after green/yellow arrow
Lagging green arrowLagging green arrow
Flashing yellow arrow with thru red ballFlashing yellow arrow with thru red ball
Video – Video – YankeeYankee Doodle (Dakota 28) at Coachman Doodle (Dakota 28) at Coachman
Video – Video – YankeeYankee Doodle (Dakota 28) at Coachman Doodle (Dakota 28) at Coachman
Design CriteriaDesign Criteria
Must have a dedicated left turn laneMust have a dedicated left turn lane
Must have dedicated indicationMust have dedicated indication
Must have presence detection on non- Must have presence detection on non- recall approachrecall approach
Enforcement ConsiderationsEnforcement Considerations
Enforcement most Enforcement most know left turn operationknow left turn operation
Important to keep crash Important to keep crash recordsrecords
The flashing yellow arrow todayThe flashing yellow arrow today
No accidents attributed to the FYA locallyNo accidents attributed to the FYA locally Federal MUTCD approval; FYA published Federal MUTCD approval; FYA published
in 2009 manual in 2009 manual Any Minnesota agency can install a FYAAny Minnesota agency can install a FYA MN/DOT plans on installing additional FYA MN/DOT plans on installing additional FYA
& standard design in new signals& standard design in new signals Nation wide installations; 500 intersectionsNation wide installations; 500 intersections Has been accepted by the traveling publicHas been accepted by the traveling public
