Traffic Signs

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Traffic Signs

• CE740 Traffic Engineering

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Introduction

• Traffic control devices
• Medium of communication between traffic engineer
  and road users
• Major types
• Traffic signs
• Road markings
• Traffic signals
• Parking control

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Traffic control devices

• Purpose
• to promote highway safety and efficiency by
  providing for the orderly movement of all road
  users
• Traffic control devices notify road users of
  regulations and provide warning and guidance
  needed for the reasonably safe, uniform, and
  efficient operation of all elements of the
  traffic stream

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Traffic control devices

• Traffic control devices or their supports shall
  not bear any advertising message or any other
  message that is not related to traffic control.
• Tourist-oriented directional signs and Specific
  Service signs are not considered advertising
  rather, they are classified as motorist service
  signs

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Traffic control devices

• Principles
• Fulfill a need
• Command attention from road user
• Convey clear and simple meaning
• Avoid overuse, misusing, confusing messages
• Adequate time for proper response
• Uniformity of the meaning of the control devices

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Traffic control devices

• Communication tools
• Color
• easily noticed characteristics
• red, green, yellow, black, blue, and brown
• Shape
• the second element discerned by the driver
• circular, triangular, rectangular, diamond shape
  
• Legend
• Pattern

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Traffic control devices

• Communication tools
• Legend
• legend should be short, simple and specific
• Symbols that are trans-lingual or word messages
• Word messages should be as brief as possible
• All lettering shall be in capital letter
• Word messages on street name and destinations may
  include lower-case letters with initial
  upper-case letters

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Traffic control devices

• Communication tools
• Pattern
• Used in markings to complement signs
• solid, double solid and dotted lines

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Traffic control devices

• Design principles
• High visibility by day and night
• High legibility
• adequately sized letters or symbols, and a short
  legend for quick comprehension
• Uniformity in design
• include shape, color, dimensions, legends,
  borders, and illumination or retro-reflectivity

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Traffic Signs

• Regulatory signs
• Mandatory signs - give notice of traffic laws or
  regulations
• Warning signs
• Cautionary signs - give notice of a situation
  that might not be readily apparent
• Informative signs
• Guide signs - show route designations, distances,
  services, points of interest, etc.

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Regulatory signs

• Types
• Right of way series
• Speed series
• Movement series
• Parking series
• Pedestrian series

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Regulatory signs

• ROW series
• STOP sign
• Octagonal shape
• to indicate traffic is always required to stop

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Regulatory signs

• STOP sign warrant
• engineering judgment indicates
• Intersection of a minor road with a major road
• Street entering a through highway or street
• Un-signalized intersection in a signalized area
• High speeds, restricted view, or crash records

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Regulatory signs

• STOP sign placement

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Regulatory signs

• ROW series
• YEILD or GIVEWAY
• downward-pointing equilateral triangle
• Wide red border and the legend YIELD in red on a
  white background

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Regulatory signs

• YEILD sign warrant
• Ability to see all conflicting traffic is
  sufficient to allow a road user to pass through
  the intersection in a reasonably safe manner.
• In a merging situation the entering roadway has
  poor geometry and/or inadequate sight distance
• An intersection where a special problem exists
  which could be corrected

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Regulatory signs

• YIELD sign placement

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Regulatory signs

• Speed series- warrants
• Road characteristics, shoulder condition, grade,
  alignment, and sight distance
• Roadside development and environment
• Parking practices and pedestrian activity
• Accidents in least a 12-month period
• Black legend on a white background
• Circular in shape with red borders

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Regulatory signs

• Speed series- warrants
• Black legend on a white background
• Circular in shape with red borders

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Regulatory signs

• Movement series
• turn prohibitions

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Warning Signs

• Purpose
• Own safety of drivers
• Extra vigilance from driver
• Design
• Legend will be black in color with a white
  background
• Shape is upward triangular or diamond shape with
  red borders

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Warning Signs

• Examples

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Traffic Signs

• Informative signs
• Predominantly meant for drivers who are
  unfamiliar to the place

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Traffic Signs
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Traffic Signs
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Thank You

• tomvmathew_at_gmail.com