Traffic Signs
A device mounted on a fixed support (permanent signs) or portable support (temporary signs) whereby a specific message is conveyed by means of words or symbols placed or erected for the purpose of regulating, warning or guiding traffic.
Regulatory Signs
Signs that inform road users of traffic laws and regulations which, if disregarded, will constitute an offense.
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Flashcards about traffic signs and road design elements, extracted from lecture notes.
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Traffic Signs
A device mounted on a fixed support (permanent signs) or portable support (temporary signs) whereby a specific message is conveyed by means of words or symbols placed or erected for the purpose of regulating, warning or guiding traffic.
Regulatory Signs
Signs that inform road users of traffic laws and regulations which, if disregarded, will constitute an offense.
Special Instruction Signs
Signs that instruct road users to meet certain traffic rule requirements or road conditions.
Warning Signs
Signs that warn road users of conditions on or adjacent to the road that may be unexpected or hazardous.
Guide Signs (Informative Signs)
Signs that inform and advise road users of directions, distances, routes, the location of services, and points of interest.
Roadwork Signs
Signs that warn or advise of temporary hazardous conditions that could endanger road users or the men and equipment engaged on roadwork.
Overhead Signs
Signs which provide means of displaying essential traffic information on wide multi-lane roads, where some degree of lane use control is required, or where side-of-road clearance is insufficient to accommodate a road side sign.
Barriers
Highway appurtenances designed to prevent vehicular penetration from the travel way to areas behind the barrier such as to minimize damage to impacting vehicles and their occupants, and to reduce the risk of injuries to pedestrians and workers.
Flashing Lamps
Warning devices used to supplement other controls and devices necessary to alert motorists of construction and maintenance activities or obstructions in the roadway.
Delineators
Light retro-reflecting devices mounted at the side of the roadway, in series, to indicate the roadway alignment.
Traffic Cones
Devices which may be conical in shape or tubular-shaped capable of performing channelization of traffic which may be set on the surface of the roadway or rigidly attached for continued use.
Temporary Curbing
Roadwork devices consisting of pre-cast concrete sections, sandbag, and others which, may be used to guide traffic at the construction site.
Flexible Post or Bollard
Device used in place of rigid barrier posts or traffic cones with a minimum of 450 mm by 50 mm wide with alternate bands of contrasting color as seen by approaching traffic for delineation of traffic.
Red (Sign Color)
Used as a background for STOP signs, as border color on GIVE WAY signs, warning signs and prohibitive signs in the regulatory type.
Black (Sign Color)
Used as legend color for signs having white, yellow, orange, fluorescent orange, fluorescent yellow green background and as chevron for hazard makers.
Yellow (Sign Color)
Used as background color for road signs.
White (Sign Color)
The background color for most signs and legends for some colored backgrounds.
Fluorescent Yellow Green (Sign Color)
Used as background color for signs related to pedestrian movement, school zones, and road work hazard markers to give additional emphasis and guidance to vehicle operators.
Fluorescent Orange (Sign Color)
Used as background color for roadwork signs whose legends relate to personal working.
Green (Sign Color)
Used as background color for direction signs.
Blue (Sign Color)
Used as background color for service signs.
Brown (Sign Color)
Reserved as background color for all tourist facility directional and information signs.
Classifications of Signs
Regulatory, Warning, Guide, Expressways, Special Purposes and Hazard Markers
Five basic requirements of effective road signs
Fulfill a need, Command attention, Convey a clear, simple message, Command respect; and Give adequate time for proper response
Classification of Regulatory Signs
Priority Signs, Direction Signs, Prohibitive or Restrictive Signs, Speed Signs, Parking Signs and Miscellaneous Signs
Four Sizes for Regulatory Signs
Size A for urban low speed roads, Size B for rural roads with speed limits between 60 and 70 kph, Size C for high speed rural highways’ multi-lane urban roads and Size D for Expressways
Classification of Warning Signs
Horizontal Alignment Signs, Intersection and Junction Signs, Advance Warning of Traffic Control Device Signs, Road Width Signs, Road Obstacle Signs, Pedestrian and School Signs, Railway Level Crossing, Supplementary Signs and Other Warning Signs
Directional Signing Series Classifications
Those installed in advance of the intersection, Those installed at the intersection, Those on departure from the intersection and Those installed on expressways
Classification of Guide Signs
Advance Direction Sign, Intersection Direction Sign, Reassurance Direction Sign, Finger Board Direction Sign, Street Name Signs, Town Name and Geographical Feature Signs, Service Signs, Tourist Information and Tourist Destination Signs and Route Markers
One-Way hazard markers uses
To delineate an abrupt narrowing of pavement, for example, at a lane drop, At exposed ends of raised median islands where traffic is required to pass to one side, On central island of a roundabout facing entering traffic and To delineate the curve approach just prior to entering an intersection
Pavement Markings Limitations
They are subject to traffic wear and require proper maintenance, They may not be clearly visible if the road is wet or dusty, They may be obscured by traffic, Their effect on skid resistance requires careful choice of materials and They cannot be applied on unsealed roads
Planning Expressways elements to consider
No frontage access, Development set well back from the highway, Grade separated intersections for extremely high flows and other intersecting expressways, Number of intersections to be minimized and Where necessary or for emergency purposes, parking/stopping to be provided clear of the main carriageway
Planning National Roads elements to consider
Limited frontage access, Development set well back from the highway, All access to premises provided via provincial roads, Number of intersections to be minimized, Suitable at-grade channelized intersections for minor flows and other elements and No roadside vendors
Yellow Pavement Markings
Double yellow no-passing lines, Unbroken portion of no-passing lines, Curb markings for prohibition of parking, On islands in line of traffic, Bus and PUJ lanes, and Keep Intersection Open markings
Red Pavement Markings
No Loading/Unloading Zone and Fire lane zone
Factors to consider when choosing a Design Speed
Function of the road, Anticipated operating speed and Anticipated speed limit
Warrants for Marking Center Lines
Two lane road (greater than 6 m in width) carrying an Annual Average Daily Traffic (ADT) in excess of 1000 vehicles, Two lane road (less than 6 m but more than 5 m in width) carrying an ADT in excess of 300 vehicles and Winding roads with widths of 5 m or more
Barrier lines may consist of either
Two unbroken yellow lines, Single unbroken yellow line and Single yellow line with a broken white line
Cases where barrier lines should be used
As center lines on approaches to signalized intersections, As center lines of multi-lane roads where overtaking must be prohibited, because of sign restrictions, ‘No-Passing’ zones where there is a restricted sight distance due to horizontal or vertical curves, or both and As center lines on approaches to railway crossings
Warrants for Use of Raised Pavement Markers
In hilly areas where fog and rain are frequently the causes of traffic accidents and In winding roads and accident prone areas
The provision of safety sight distance depends on the characteristics of the driver such as
Alertness of driver, Recognition of the hazard and Actions available to the driver – to stop or to change direction
The provision of safety sight distance depends on the characteristics of the vehicle such as
Type of vehicle – car or truck, Friction between the tire and the road, Eye height of the driver and Speed of vehicles
The provision of safety sight distance depends on the characteristics of the road environment such as
Road geometry – grade and curvature sight limitations, Road surface – sealed or unsealed, smooth or rough and Road illumination at night
Each type of sight distance consists of three elements:
Driver Eye Height, Object Height and Sight Distance
Two components in stopping sight distance
Reaction distance – the distance traveled while the driver perceives a hazard, decides to take action, then acts by starting to apply the brakes to start slowing down and Braking distance – the distance required for the vehicle to slow down and stop
Four different criteria used for the establishment of sag vertical curves
Headlight sight distance, Passenger comfort, Drainage control and General appearance
Shoulder paving is a valuable method of providing
Integrity of the pavement, Width to place edgeline pavement markings, Additional safety to prevent vehicles skidding or drivers losing control in gravel and Low maintenance costs compared with unpaved shoulders
Element of Berthing Facility
Planned Water Depth, Design Water Depth, Coping/Crown Elevation, Length - Standard Part, Approach Part, Width of Apron and Slope of Apron
Four types of escape ramps
Sand Pile, Descending Grade, Horizontal Grade and Ascending Grade
Types of intersections that generally exist on the road network are
Unflared and unchannelized intersections (without widening or traffic islands), Flared and unchannelized intersections (with widening but without traffic islands) and Channelized intersections (traffic islands to guide traffic)
Principles of good design to reduce the likelihood of traffic accidents include
Minimize the speed of vehicles at potential collision points, Separate movements and points of conflict by channelization, or in some situations, prohibit certain movements (and provide for them at other intersections along the route), Control movements to reduce the possibility of conflict and Clearly define vehicle paths by use of pavement markings
Harbor
A protected water area to provide safe and suitable accommodation for ships for the transfer of cargo, refueling, repairs, etc.
Natural harbors
harbors protected from storms and waves by the natural configuration of the land
Semi-natural harbors
harbors with both natural and artificial protection
Artificial harbors
harbors protected from the effect of waves by means of breakwaters, or harbors created by dredging.
Port
A sheltered place where the ship may receive or discharge cargo. It includes the harbor with its approach channels and anchorage places.
Ocean ports
ports located on coasts, tidal estuaries or river mouths where the port can be reached directly by ocean-going ships.
Inland waterway ports
ports located on navigable rivers, channels and lakes.
Fairway
a navigable channel in a harbor, offshore etc; the usual course taken by vessels in such places.
Berth
A place where the ship can moor. In the case of a quay or jetty structure, it will include the section of the structure where labor, equipment and cargo move to and from the ship.
Berth structure
An artificial landing place for the loading and unloading of ships.
Wharf
A continuous structure built parallel to along the margin of the sea or alongside riverbanks, canals, or waterways where vessels may lie alongside to receive or discharge cargo, embark or disembark passengers or lie at rest
Quay
this term can be substituted to wharf when applied to great solid structures in large ports
Pier
Any structure built into the sea but not parallel to the coastline and includes any stage, stair landing place, landing stage jetty, floating barge, and pontoon, any bridge or other works connected there with.
Jetty
a landing stage or small pier at which boats can dock or be moored.
Dolphin
a berth structure for mooring the ship on the open sea; An isolated piled or gravity structure used either to maneuver a ship or to facilitate holding it in position at its berth.
Dry Dock
a type of dock consisting of a rectangular basin dug into the shore of a body of water and provided with a removable enclosure wall or gate on the side toward the water, used for major repairs and overhaul of vessels.
Significant Wave (significant wave height H1/3 and significant wave period T1/3)
The waves in a wave group are rearranged in the order of their heights and the highest one- third are selected; the significant wave is then the hypothetical wave whose height and period are the mean height and period of the selected waves.
Highest Wave (highest wave height Hmax and highest period Tmax)
is the highest wave in a wave group.
Highest One-Tenth Wave (H1/10, T1/10)
is the wave whose height and period are equal to the mean height and period of the highest one-tenth of the waves in a wave group.
Mean wave (mean wave height H , mean period T )
is the wave whose height and period are equal to the mean height and period of all of the waves in a wave group.
Deepwater Waves (deepwater wave height H0 and deepwater wave period T0)
is the wave at a place where the water depth is at least one- half of the wavelength; the wave parameters are expressed with those of the significant wave at this place.
Equivalent Deepwater Wave Height (H0’)
is a hypothetical wave height that has been corrected for the effects of planar topographic changes such as refraction and diffraction; it is expressed with the significant wave height.
Wave Refraction
occurs in intermediate depth to shallow waters. The change in wave height and wave direction due to the change in local wave velocity caused in water depth.
Wave Diffraction
is a phenomenon whereby waves wheel into region that is screened by something like a breakwater.
Wave Reflection
the waves reflected from port and harbor facilities can exercise a large influence on the navigation of vessels and cargo handling.
Wave Shoaling
shoaling is one of the important factors that lead to changing of the wave height in coastal waters. It exemplifies the fact that the wave height in shallow waters is also governed by the water depth and wave period.
Wave Breaking
At places where the water depth is no more than about three times the equivalent deepwater wave height decreases rapidly of the wave height due to wave breaking shall be considered.
Astronomical tide
is the periodic rise and fall of sea level in response to the gravitational attraction of the sun and moon as modified by the earth’s rotation.
Mean Sea Level (MSL)
is the average of the sea water surface for all stages of the tide over a 19- year period.
Mean Low Water (MWL)
is the height of the low water over a 19-year period.
Mean Lower Low Water (MLLW)
is the average height of the lower low waters over a 19-year period.
Mean High Water (MHW)
is the average height of the high waters over a 19-year period.
is the average height of the higher high water over a 19-year period.
Storm Surge
Storm Surge
is abnormal rise of the sea level that occurs when a typhoon passes by.
Tsunamis
are wave with an extremely long period that mainly occur when there is a sudden large- scale sea floor movement usually associated severe, shallow focus earthquake.
Seiche
is a phenomenon involving abnormal oscillations of the water level with a period of approximately a few minutes to a few tens of minutes.