Traffic Control Devices Presented By: Team Hawaii
5 Basic Needs: Fulfill a need Command attention Command respect from roadway users Convey clear and simple message Give adequate time for proper response
Purpose: Promote highway safety and efficiency Notify road users of changes and regulations Provide guidance for changes and minimize incidents
Types of Devices Signs Signals Markings Delineators Barricades Other
Placement Uniform and consistent Shall be authorized by the public agency or official having jurisdiction (i.e. _DOT) Federal minimum can be found in the MUTCD Typical Applications and respective tables (Chapter 6F)
Signs Regulatory Signs Warning Signs Guide Signs Dimensions Applications Requirements
Regulatory Signs Reinforces traffic laws and regulations Requires authorization from regulatory agency Size and color standards determined regulatory authority Color: black, white and red
Warning Signs Indicates warnings to road user of conditions on or near the road Placed in advance of hazardous condition Generally diamond shaped Color If permanent= black on yellow If temporary= black on orange
Guide Signs Provide road users with guidance during travel Include, but are not limited to: Route signs Destination/Distance signs Toll Signs
Guide Signs Colors include: Green Blue Brown Purple
Dimensions/Applications/Requirements Sign dimensions regulated by MUTCD and derived by posted speed Placement Right side of road, generally Both sides of road if median allows Permanent signs: 7’ off ground Temporary signs: 1’ off ground
Dimensions/Applications/Requirements Cont. Retroreflectivity Increases night time visibility Required for permanent signage Required for temporary night signage Not required for temporary day time signage
Arrow Boards Shall provide additional warning and directional information. Assist in merging and controlling traffic in work zones using TTC Requirements found in MUTCD Part 6 Chevrons are acceptable, but arrows are preferred
Message Boards (PCMS) Portable Changeable Message Signs Best used in areas with heavy traffic and/or difficult/variable road conditions Found to have better response to roadway users than advanced warning signs Best to pair with advanced warning signage Message must be clear and simple
Channelizing Devices and Delineators Cones Drums Tubular Markers Vertical Panels Barricades Type I Type II Type III
Cones Predominantly Orange Minimum height Daytime- 18” Night time- 28”, but may be 36”- check with jurisdiction At night, must be retroreflectorized 4”-6” wide white stripes Min. 2 white and 2 orange stripe, with orange stripe on top
Drums Generally used on highways and freeways Constructed of lightweight, deformable materials. Metal drums are prohibited Min. 36” height and have at least an 18” min. width regardless of orientation
Drums Min. 2 white and two orange 4”-6” retroreflective stripes required Ballast shall not be placed on the top of the drum
Tubular Marker Limited visibility to driver and should only be used where space restrictions do not allow for other devices Predominantly Orange
Tubular Marker Minimum height Daytime, low speed- 18” tall Highway/Freeway- 28” tall Night time- 42” 2” wide facing road users Retroreflectorization with four 4”-6” wide alternating orange and white stripes, with orange on top
Vertical Panels Where space is limited, may be used to: Channelize vehicular traffic Divide opposing lanes Replace barricades
Vertical Panels Shall have retroreflective striped material that is 8”-12” in width and at least 24” in height Alternating orange and white retroreflective stripes slope down at an angle of 45 degrees in the direction of traffic
Type I,II, and III Barricades Portable or fixed device Has one to three rails with appropriate markings Used to: Control road users Restrict Delineate all or a portion of the right-of-way
Type I,II, and III Barricades Stripes shall slope downward at an angle of 45 degrees toward the direction road users are going to pass
General Delineator Rules Retroreflective required at night Yellow is when used to channelize traffic in opposite directions Face chevrons towards direction that traffic will travel
General Delineator Rules Always look at specific jurisdiction to see requirements Utilize barrier lights (i.e. Steady Burns) for night operations
Temporary Traffic Barriers Types of Barriers K-rail/Jersey Barrier Street Rail Triton Barrier/Water filled
Temporary Traffic Barriers 4 Primary functions To keep vehicular traffic from entering work zone To separate workers, bicyclists, and pedestrians from motor vehicle traffic To separate opposing directions of vehicular traffic To separate vehicular traffic, bicyclists, and pedestrians from exposed objects (i.e. false work)
Crash Cushions Formally known as attenuators Purpose: To eliminate blunt ends of barriers and lessen impact Types of crash cushions: Redirective Non-redirective (i.e. Absorb 350) Truck mounted attenuators Always read manufacture's specifications and know product’s clear zone
Crash Cushions Cont. Considerations when choosing: Permanent, work zone, or specialty? Clear zone of specific attenuator Posted speed of travel way Cost
Pavement Markings Permanent Markings: Indicate the separation of lanes for roadways users Assist the bicyclist by indicating assigned travel paths Provide advance information for turning and crossing maneuvers Temporary Markings Must be replaced during construction See project contract for required specification
Pavement Markings Cont. Normal line- 4”-6” wide Markings shall be: Yellow: Separate traffic traveling in oppose direction White: Right hand edge of roadway Raised Red Markers: One-way roadways, ramps, or travel lanes that are not to be crossed Blue: supplement white markings for parking for ADA areas Purple: Supplement lane or edge line marking toll plaza approach lanes.
Rumble Strips Transverse areas of rough-textured or slightly raised or depressed road surface Purpose: Alert drivers to unusual vehicular traffic conditions Through noise and vibration they attract the drivers attention to such features Should not be placed on sharp horizontal or vertical curves Should not be placed through pedestrian crossings or bicycle routes
Screens AKA: “Gawk” Screens Purpose: Block the road users’ view of activities that can be distracting and reduce headlight glare from oncoming motor vehicle traffic Design should be in accordance with Chapter 9 of AASHTO’s “Roadside Design Guide”
References Manual on Uniform Traffic Control Devices for Streets and Highways. [Washington, D.C.]: U.S. Dept. of Transportation, Federal Highway Administration, 2009. Print. Roadside Design Guide. Washington, D.C.: American Association of State Highway and Transportation Officials, 2011. Print