Accessible Pedestrian Signals Presented by: Joe Couples, P.E. Valerie Lee, P.E.
Dec 17, 2015
Accessible Pedestrian Signals
Presented by:
Joe Couples, P.E.
Valerie Lee, P.E.
Legacy devices remain...but mostly new technology.
Seattle APS
Accessible Pedestrian Signals(APS)
MUTCD 4E.06• Both audible and vibro-tactile modes
identified for walk indication.• Locator tone identified in support section.• Provides guidance for factors that should
be considered in study of when to install an Accessible Pedestrian Signal.
• APS cannot be by TOD operation.
Study Factors to Consider
• Potential demand (needs) for APS.• Requests.• Traffic Volumes, and turning movements.• Signal complexity.• Intersection complexity
Potential Demand
• High Volume Transit facilities such as Streetcar and LRT stations.
• Transit hubs and transfer points.• Libraries or other facilities for the blind.• Recreation facilities.
Requests
In Seattle:• Until LINK Light Rail and the South Lake
Union Streetcar, almost all of the APS installations were based upon requests.
• Almost all requests were to meet transit, shopping, and employment needs of individual(s).
Traffic Volumes
• Pedestrians may be present at any time.• Low Volumes.• High turning volume percentage.
Traffic Signal Complexity
• Split-Phasing.• Protected Left or Right-Turns.• Leading Pedestrian Intervals (LPI).• Exclusive pedestrian phase.• Other complicated signal operation.
Split Phasing
Intersection Complexity
• Skewed intersection geometry.• Median islands.• Free right-turn islands.• Signal complexity.• Intersection complexity
Intersection Skew
Traffic island
APS Design Best Practice
Design Complications
• Underground utilities, MH & JB's.• Curb ramps.• Decorative poles.• Light and heavy rail adjacent or in ROW.
Design Complications
Median Island APS
Over-Engineering?
Errors or Design Standards?
Which is Correct?
Office Engineering?
APS in Operation
• Actuated operation.• Pre-timed/recall operation.• APS Controller Unit.
Actuated Operation
• Pedestrian pushes button to activate.• Audible and vibro-tactile activate with
“Walk” indication.• Returns to holding mode with “ Flashing
Don't Walk”.
Pre-timed Operation in Seattle
• “Walk” interval comes on automatically without the audible & vibro-tactile.
• Some devices able to activate audible & vibro-tactile if adequate clearance time.
• Returns to holding mode with “ Flashing Don't Walk”, PBS indicator light goes on.
APS Settings
• Locator tone is used.• Audible and locator tone volume settings
are independently adjustable.• Volume adjusts to ambient noise so as to
be quieter at night and other periods.
Noise Complaints
• Few complaints regarding audible indications.
• Complaints regarding audible mostly by multi-story condo or apartment dwellings.
• Many complaints regarding locator tone in residential areas.
APS Prioritization
Post InstallationCheck List
APS Sign Message
Web Resources
• NCHRP Web Document 117A, Accessible Pedestrian Signals: A Guide to Best Practices. June 2007
• MUTCD 2009
Questions?