Traffic Signs Transportation Systems Engineering 20080821 Traffic Signs

Traffic Signs Transportation Systems Engineering 20080821 Traffic Signs

Introduction • Traffic control devices – Medium of communication between traffic engineer and road users • Major types: – Traffic signs – Road markings – Traffic signals – Parking control 20080821 Traffic Signs 2

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 20080821 Traffic Signs 3

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 20080821 Traffic Signs 4

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 20080821 Traffic Signs 5

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 20080821 Traffic Signs 6

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 uppercase letters 20080821 Traffic Signs 7

Traffic control devices • Communication tools – Pattern • Used in markings to complement signs • solid, double solid and dotted lines 20080821 Traffic Signs 8

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 20080821 Traffic Signs 9

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. 20080821 Traffic Signs 10

Regulatory signs • Types – Right of way series – Speed series – Movement series – Parking series – Pedestrian series 20080821 Traffic Signs 11

Regulatory signs • ROW series – STOP sign – Octagonal shape – to indicate traffic is always required to stop 20080821 Traffic Signs 12

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 20080821 Traffic Signs 13

Regulatory signs • STOP sign placement 20080821 Traffic Signs 14

Regulatory signs • ROW series – YEILD or GIVEWAY – downward-pointing equilateral triangle – Wide red border and the legend YIELD in red on a white background 20080821 Traffic Signs 15

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 20080821 Traffic Signs 16

Regulatory signs • YIELD sign placement 20080821 Traffic Signs 17

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 20080821 Traffic Signs 18

Regulatory signs • Speed series- warrants – Black legend on a white background – Circular in shape with red borders 20080821 Traffic Signs 19

Regulatory signs • Movement series – turn prohibitions 20080821 Traffic Signs 20

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 20080821 Traffic Signs 21

Warning Signs • Examples 20080821 Traffic Signs 22

Traffic Signs • Informative signs – Predominantly meant for drivers who are unfamiliar to the place 20080821 Traffic Signs 23

Traffic Signs 20080821 Traffic Signs 24

Traffic Signs 20080821 Traffic Signs 25

Thank You tomvmathew@gmail. com 20080821 Traffic Signs