MSTE TERMS Transportation PDF

Definition of Terms Classifications of signs Traffic Signs - device mounted on a fixed support (permanent Signs are classified in the following groups according to their use. signs) or portable support (temporary signs) whereby a specifi...

Definition of Terms Classifications of signs Traffic Signs - device mounted on a fixed support (permanent Signs are classified in the following groups according to their use. signs) or portable support (temporary signs) whereby a specific Regulatory Signs message is conveyed Warning Signs by means of words or symbols placed or erected for the purpose Guide Signs or Informative Sign of regulating, warning or guiding traffic. Signs for Expressways Regulatory Signs - signs that inform road users of traffic laws Signs for Special Purposes and regulations which, if disregarded, will constitute an offense. Hazard Markers Special Instruction Signs - signs that instruct road users to meet certain traffic rule requirements or road condition Uniformity of application is as important as standardization with Warning Signs - warn road users of condition on or adjacent to respect to design and placement. Identical conditions should the road that may be unexpected or hazardous always be treated with the same type of signs so that road users Guide Signs (Informative Signs) - inform and advice road users can readily anticipate the course of action required. of directions, distance, routes, the location of services, and points of interests To be effective, the road sign should meet the five basic Roadwork Signs - warn or advise of temporary hazardous requirements: conditions that could endanger road users or the men and Fulfill a need equipment engaged on roadwork Command attention Overhead Signs - signs which provide means of displaying Convey a clear, simple message essential traffic information on wide multi-lane roads, where some Command respect; and degree of lane use control is required, or where side-of-road Give adequate time for proper response clearance is insufficient to accommodate a road side sign It should be noted that when all sign rules have been followed, Barriers - highway appurtenances designed to prevent vehicular some visual judgment must be exercised in adjusting sign penetration from the travel way to areas behind the barrier such elements. The following general rules are to be applied when as to minimize damage to impacting vehicles and their occupants, designing the sign face. and to reduce the risk of injuries to pedestrians and workers Cramping of legend is to be avoided; Flashing Lamps - warning devices used to supplement other Avoid large areas of blank panel, particularly blank areas not controls and devices necessary to alert motorists of construction symmetrically disposed across the panel; and maintenance activities or obstructions in the roadway. If there are two list of legends side by side (e.g., as on Delineators - light retro-reflecting devices mounted at the side of Reassurance Signs) it is necessary to left justify the left list and the roadway, in series, to indicate the roadway alignment. right justify the right list; and, Traffic Cones - devices which may be conical in shape or tubular- Elements such as arrows and symbols may sometimes have to be shaped capable of performing channelization of traffic which may larger than the principal legend would normally require. For be set on the surface of the roadway or rigidly attached for example, an arrow relates to several lines of legends on a direction continued use sign Temporary Curbing - roadwork devices consisting of pre-cast concrete sections, sandbag, and others which, may be used to Classification of Regulatory Signs guide traffic at the construction site. Priority Signs Flexible Post or Bollard - device used in place of rigid barrier Direction Signs posts or traffic cones with a minimum of 450 mm by 50 mm wide Prohibitive or Restrictive Signs with alternate bands of contrasting color as seen by approaching Speed Signs traffic for delineation of traffic. Parking Signs Miscellaneous Signs The standard colors for signs are as follows: Red is used as a background for STOP signs, as border color on Four Sizes for Regulatory Signs GIVE WAY signs, warning signs and prohibitive signs in the Size A for urban low speed roads; regulatory type. Size B for rural roads with speed limits between 60 and 70 kph; Black is used as legend color for signs having white, yellow, orange, Size C for high speed rural highways’ multi-lane urban roads fluorescent orange, fluorescent yellow green background Size D for Expressways and as chevron for hazard makers. Yellow is used as background color for road signs. Classification of Warning Signs White is the background color for most signs and legends for some Horizontal Alignment Signs colored background. Intersection and Junction Signs Fluorescent Yellow Green is used as background color for signs Advance Warning of Traffic Control Device Signs related to pedestrian movement, school zones, and road Road Width Signs work hazard markers to give additional emphasis and Road Obstacle Signs guidance to vehicle operators. Pedestrian and School Signs Fluorescent Orange is used as background color for roadwork Railway Level Crossing signs whose legends relate to personal working. Supplementary Signs Green is used as background color for direction signs. Other Warning Signs Blue is used as background color for service signs. Brown is reserved as background color for all tourist facility directional and information signs. Signs in Directional Signing series are usually classified into four Red shall be used in: categories: No Loading/Unloading Zone; and Those installed in advance of the intersection. Fire lane zone Those installed at the intersection. Those on departure from the intersection. Design Speed Those installed on expressways. The choice of an appropriate design speed for a road project is important to ensure a safe design. Classification of Guide Signs When choosing a design speed, the following factors need to be Advance Direction Sign considered: Intersection Direction Sign Function of the road Reassurance Direction Sign Anticipated operating speed Finger Board Direction Sign Anticipated speed limit Street Name Signs Town Name and Geographical Feature Signs Warrants for Marking Center Lines Service Signs A center line may be marked on an urban or rural road if one or Tourist Information and Tourist Destination Signs more of the following conditions are met: Route Markers Two lane road (greater than 6 m in width) carrying an Annual Average Daily Traffic (ADT) in excess of 1000 vehicles; One-Way hazard markers indicate to the approaching driver the Two lane road (less than 6 m but more than 5 m in width) direction to be followed if the marker appears in the driving path. carrying an ADT in excess of 300 vehicles; and They may point to the left or right as appropriate and are used as Winding roads with widths of 5 m or more. follows: To delineate an abrupt narrowing of pavement, for example, at a Barrier lines may consist of either: lane drop; Two unbroken yellow lines; At exposed ends of raised median islands where traffic is Single unbroken yellow line; or, required to pass to Single yellow line with a broken white line. one side; On central island of a roundabout facing entering traffic; and The following are the cases where barrier lines should be used: To delineate the curve approach just prior to entering an As center lines on approaches to signalized intersections; intersection. As center lines of multi-lane roads where overtaking must be prohibited, because of sign restrictions; Pavement markings have definite limitations: ‘No-Passing’ zones where there is a restricted sight distance due They are subject to traffic wear and require proper maintenance; to horizontal or vertical curves, or both; and They may not be clearly visible if the road is wet or dusty; As center lines on approaches to railway crossings They may be obscured by traffic; Warrants for Use Their effect on skid resistance requires careful choice of Because of the high cost of installation and maintenance, use of materials; and raised pavement markers may be considered only in the following They cannot be applied on unsealed roads. condition: In hilly areas where fog and rain are frequently the causes of The elements to consider when planning Expressways are: traffic accidents; and No frontage access; In winding roads and accident prone areas. Development set well back from the highway; Grade separated intersections for extremely high flows and other The provision of safety sight distance depends on the intersectingexpressways; characteristics of the driver such as: Number of intersections to be minimized and Alertness of driver Where necessary or for emergency purposes, parking/stopping Recognition of the hazard to be provided clear of the main carriageway. Actions available to the driver – to stop or to change direction The elements to consider when planning National Roads are: The provision of safety sight distance depends on the Limited frontage access characteristics of the vehicle such as: Development set well back from the highway Type of vehicle – car or truck All access to premises provided via provincial roads Friction between the tire and the road Number of intersections to be minimized Eye height of the driver Suitable at-grade channelized intersections for minor flows and Speed of vehicles other elements The provision of safety sight distance depends on the No roadside vendors characteristics of the road environment such as: Road geometry – grade and curvature sight limitations Color of Pavement Markings Road surface – sealed or unsealed, smooth or rough The color of pavement markings shall be white except for the Road illumination at night alternative uses of yellow as specified below: Each type of sight distance consists of three elements: Double yellow no-passing lines; Driver Eye Height Unbroken portion of no-passing lines; Object Height Curb markings for prohibition of parking; Sight Distance On islands in line of traffic; Bus and PUJ lanes; and, Keep Intersection Open markings There are two components in stopping sight distance: PORTS AND HARBORS Reaction distance – the distance traveled while the driver Harbor - A protected water area to provide safe and perceives a suitable accommodation for ships for the transfer of hazard, decides to take action, then acts by starting to apply the cargo, refueling, repairs, etc. Harbors may be subdivided brakes to into: start slowing down; and a. Natural harbors: harbors protected from Braking distance – the distance required for the vehicle to slow storms and waves by the natural configuration down and of the land. stop b. Semi-natural harbors: harbors with both natural and artificial protection. Four different criteria used for the establishment of sag vertical c. Artificial harbors: harbors protected from the curves: effect of waves by means of breakwaters, or Headlight sight distance harbors created by dredging. Passenger comfort Drainage control Port – A sheltered place where the ship may receive or General appearance discharge cargo. It includes the harbor with its approach channels and anchorage places. Ports may be subdivided PPA has used MLLW as the datum line for design of port facilities into: in accordance with charts. But there are many ports of which low a. Ocean ports: ports located on coasts, tidal tide go down very often below MLLW. estuaries or river mouths where the port can be reached directly by ocean-going ships. For instance: (Port Cebu) b. Inland waterway ports: ports located on According to the tide table (1991) of NAMRIA, the frequency of navigable rivers, channels and lakes. tide below MLLW is 213 times/year and the maximum amount of the value is -0.51 m. Under this condition it is dangerous for ships Fairway - a navigable channel in a harbor, offshore etc; to utilize the port. the usual course taken by vessels in such places. Shoulder paving is a valuable method of providing: Integrity of the pavement Berth - A place where the ship can moor. In the case of a Width to place edgeline pavement markings quay or jetty structure, it will include the section of the Additional safety to prevent vehicles skidding or drivers losing structure where labor, equipment and cargo move to and control in gravel. from the ship. Low maintenance costs compared with unpaved shoulders Berth structure - An artificial landing place for the Element of Berthing Facility: loading and unloading of ships. Berth structures can be Planned Water Depth subdivided into: Design Water Depth a. Wharf - A continuous structure built parallel to Coping/Crown Elevation along the margin of the sea or alongside Length - Standard Part, Approach Part riverbanks, canals, or waterways where vessels Width of Apron may lie alongside to receive or discharge cargo, Slope of Apron embark or disembark passengers or lie at rest. There are four types of escape ramps: Quay – this term can be substituted to wharf Sand Pile when applied to great solid structures in large Descending Grade ports. Horizontal Grade Ascending Grade In stability calculation of gravity type quaywall, the following matters should be examined: Types of intersections that generally exist on the road network (a) Sliding of the wall are: (b) Bearing capacity of foundation Unflared and unchannelized intersections (without widening or (c) Overturning of the wall traffic islands) (d) Circular slip and settlement Flared and unchannelized intersections (with widening but without traffic islands) and b. Pier – Any structure built into the sea but not Channelized intersections (traffic islands to guide traffic) parallel to the coastline and includes any stage, stair landing place, landing stage jetty, floating Principles of good design to reduce the likelihood of traffic barge, and pontoon, any bridge or other works accidents connected there with. include: Minimize the speed of vehicles at potential collision points Jetty – a landing stage or small pier at which Separate movements and points of conflict by channelization, or boats can dock or be moored. in some situations, prohibit certain movements (and provide for them at other c. Dolphin: a berth structure for mooring the ship intersections along the route) on the open sea; An isolated piled or gravity Control movements to reduce the possibility of conflict and structure used either to maneuver a ship or to Clearly define vehicle paths by use of pavement markings facilitate holding it in position at its berth.  Dry Dock – a type of dock consisting of a rectangular Wave Shoaling shoaling is one of the important factors basin dug into the shore of a body of water and provided that lead to changing of the wave height in with a removable enclosure wall or gate on the side coastal waters. It exemplifies the fact that toward the water, used for major repairs and overhaul of the wave height in shallow waters is also vessels. governed by the water depth and wave period. Waves Wave Breaking At places where the water depth is no more than about three times the equivalent Significant Wave (significant wave height H1/3 and deepwater wave height decreases rapidly of significant wave period T1/3) the wave height due to wave breaking shall be considered. 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 Tides and Abnormal Water Level the hypothetical wave whose height and period Astronomical tide is the periodic rise and fall of sea level are the mean height and period of the selected in response to the gravitational attraction of the sun and waves. moon as modified by the earth’s rotation. The essential parameters to characterize the tide are: Highest Wave (highest wave height Hmax and highest a. Mean Sea Level (MSL) – is the average of the sea period Tmax) is the highest wave in a wave water surface for all stages of the tide over a 19- group. year period. b. Mean Low Water (MWL) – is the height of the Highest One-Tenth Wave (H1/10, T1/10) is the wave whose low water over a 19-year period. height and period are equal to the mean c. Mean Lower Low Water (MLLW) – is the height and period of the highest one-tenth average height of the lower low waters over a of the waves in a wave group. 19-year period. d. Mean High Water (MHW) – is the average height of the high waters over a 19-year period. Mean wave (mean wave height H , mean period T ) is e. Mean Higher High Water (MHHW) – is the the wave whose height and period are equal average height of the higher high water over a to the mean height and period of all of the 19-year period. waves in a wave group. Storm Surge is abnormal rise of the sea level that occurs Deepwater Waves (deepwater wave height H0 and when a typhoon passes by. This rise above deepwater wave period T0) is the wave at a normal level on this open coast is due to place where the water depth is at least one- atmosphere pressure reduction as well as half of the wavelength; the wave that due to wind stress. parameters are expressed with those of the significant wave at this place. Tsunamis are wave with an extremely long period that mainly occur when there is a sudden large- Equivalent Deepwater Wave Height (H0’) is a scale sea floor movement usually associated hypothetical wave height that has been severe, shallow focus earthquake. corrected for the effects of planar Seiche is a phenomenon involving abnormal oscillations of the topographic changes such as refraction and water level with a period of approximately a few minutes to a few diffraction; it is expressed with the tens of minutes. It occurs when small fluctuations of the water significant wave height. level are generated by micro-scale variations of the atmospheric pressure by an air front or a low pressure in the outer sea, and the Wave Refraction occurs in intermediate depth to shallow components of those oscillations whose period is the same as a waters. The change in wave height and natural period of the harbor are amplified through resonance. 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. For example, waves reflected from vertical breakwaters can cause disturbances in navigation channels, and multiple reflected waves from quaywalls can cause agitations within harbors.