Highways Terms PDF

The following elements are to be considered when planning Expressways: I. No frontage access II. Development set well back from the highway III. Grade separated intersections for extremely high flows and other intersecting expressways IV. Number of intersections to be minimi...

The following elements are to be considered when planning Expressways: I. No frontage access II. Development set well back from the highway III. Grade separated intersections for extremely high flows and other intersecting expressways IV. Number of intersections to be minimized V. Where necessary or for emergency purposes, parking/stopping to be provided clear of the main carriageway. — The elements to consider when planning National Roads are: I. Limited frontage access II. Development set well back from the highway III. All Access to premises provided via provincial roads IV. NUmber of intersections to be minimized V. Suitable at-grade channelized intersections for minor flows and other elements VI. No roadside vendors — Road safety is given importance in the proposed Traffic Impact Assessment guidelines. THe general scope of works on the proposed guidelines cover the following: I. Transportation Improvement II. Road Geometry III. Traffic Safety IV. Site Circulation and Parking V. Transportation demand management VI. Neighborhood traffic and parking management VII. Funding for countermeasures — When choosing a design speed for a road project, the following factors need to be considered: I. Function of the road II. Anticipated operating speed III. Anticipated speed limit IV. Economics — A speed limit of ___ or lower would be appropriate in areas where there is high pedestrian activity such as in city center areas. 40 kph ___ 60 kph Speed limit for low risk pedestrian areas is ___. On roads through built-up areas where there are not so many pedestrians, it is appropriate to allow motorized traffic to travel more quickly. ___ An ___ speed limit would be appropriate on a high standard duplicated carriageway road where there is only occasional access from adjoining properties. 80 kph ___ A ___ speed limit would only be appropriate on very high standard expressways , which have a low crash rate. 100 kph ___ It is the maximum number of vehicles, which have a reasonable expectation of passing over a given section of a lane or roadway in one direction or in both directions during one hour under prevailing road and traffic conditions. Road Capacity ___ The capacity of a route can be affected by the following factors: I. Number of lanes II. Lane and shoulder width\ III. Terrain and road gradient IV. Traffic composition  V. Side friction such as the presence of road furniture and pedestrians VI. Intersection capacity, (priority of movements, traffic signal phasing, number of lanes etc.) ___ Ideal capacity of a road is: 2000 vph ___ Vulnerable road users include: I. Pedestrians II. People with disabilities III. Non-motorized vehicles IV. Motorcycles ___ The first aim of safe road design is to ensure that road users remain safely on the road. This depends on the following factors: I. A sound road surface; II. An adequate width or cross-section; III. Horizontal and vertical alignment; IV. Good visibility/sight distance; V. Delineation and signing; VI. Provision for pedestrians, pedal cyclists and people with disabilities; VII. Management of traffic conflicts at intersections; and, VIII. Speed management ___ The areas where the state of the road surface condition and good texture of the road surface is particularly important are where vec=hicles are required to brake or maneuver suddenly such as: I. On the approach to traffic light signals II. At roundabouts III. Around tight curves IV. On downhill slopes ___ The provision of safety sight distance depends on the characteristics of the driver such as: I. Alertness of driver II. Recognition of the hazard III. Actions available to the driver - to stop r to change location ___ The provision of safety sight distance depends on the characteristics of the vehicles such as: I. Type of vehicle - car and truck II. Friction between the tire and the road III. Eye height of the driver IV. Speed of vehicles ___ The provision of safety sight distance depends on the characteristics of the road environment such as: I. Road geometry - grade and curvature sight limitations II. Road surface - sealed or unsealed, smooth or rough III. Road illumination at night ___ Each type if sight distance consists of three elements: I. Driver Eye Height is the observed eye height of a driver; II. Object Height is a possible object in the path of a vehicle; and, III. Sight Distance is dependent on design speed and vehicle type. __ There are two components in stopping sight distance: I. 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 II. Braking distance - the distance required for the vehicle to slow down and stop ___ The reaction time to be used for road safety design is ____. This value is applied to the whole range of design speeds. 2.5 seconds ___ The length of superelevation development from zero cross slope to full design superelevation os known as: Superelevation runoff ___ The length of superelevation development from the normal cross slope point on the tangent. Tangent runout ___ Minimum K value vertical curves should be selected on the basis of three controlling factors: I. Sight distance is a requirement in all situations for driver safety; II. Appearance is generally required in low fill and fat topography situations; and III. Riding comfort is a general requirement with specific need on approaches to a floodway where the length of depression needs to be minimized. ___ At least four different criteria are used for the establishment of sag vertical curves. I. Headlight sight distance II. Passenger comfort III. Drainage control and IV. General appearance ___ The basic lane width appropriate for national roads is ___. 3.35 m ___ For a single lane road traffic lane width is 4.0 m ___ For a two lane national road the minimum width is ___. 6.7 m ___ Shoulder paving is a valuable method of providing: I. Integrity of the pavement; II. Width to place edgeline pavement markings; III. Additional safety to prevent vehicles skidding or drivers losing control in gravel; and IV. Low maintenance cost compared with unpaved shoulders. ___ A type of curb suited for the edge of the traveled way where it is generally considered that drivers should not mount the curb or sidewalk. Barrier curb ___ THis type of curb provides less vaulting of the errant vehicle on impact with the curb, less likelihood of the driver losing control and less damage to occupants of the vehicles compared to barrier curbs. The mountable / drop curb ___ In flat to rolling terrain, these lanes are used to break up platoons of traffic and to improve traffic flow over a section of a road. A series of such auxiliary lanes for road. A series of such auxiliary lanes for both directions of traffic can greatly improve traffic flow and driver satisfaction. Overtaking Lanes ___ THese can be considered as a special form of overtaking lane but they are only provided on inclines. THese form part of the network of overtaking opportunities and will therefore have an effect on decisions associated with the location of other overtaking lanes. Climbing Lanes ___ This design of overtaking lanes and climbing lanes requires the consideration of the: I. Initial diverge taper; II. Auxiliary lane length; and III. End or merge taper ___ A taper is required at the start of an auxiliary lane to provide for the lateral movement of traffic. Diverge Taper ___ It is a converging of separate streams into a single stream. Merge Taper ___ It is a very short section of fully constructed shoulder or added lane that is provided to allow slow vehicles to pull aside and be overtaken. It differs from an overtaking lane due to its short length, different signing and that the majority of vehicles are not encouraged to travel in the right lane. Turn-out ___ Where long steep grades occur, it is desirable to provide emergency escape ramps. These are to be located to slow or stop an out of control vehicle away from the main traffic stream. Out of control vehicles result from drivers losing control of their vehicle. There are four types of escape ramps: I. Sand Pile; II. Descending Grade; III. Horizontal Grade; and  IV. Ascending Grade. ___ Delineation of the road alignment needs to be considered as part of the design process to ensure that adequate guidance is provided to rad users. Delineation is generally provided by the use of the following devices: I. Pavement Marking II. Signs III. Guide Posts IV. Reflective Delineators V. Lighting VI. Curb or other physical devices ___ THe types of intersections that generally exist on the road network are: I. Unflared and unchannelized intersections (without widening or traffic islands) II. Flared and unchannelized intersections (with widening but without traffic islands) III. Channelized intersections (traffic islands to guide traffic) ___ Principles of good design to reduce the likelihood of traffic accidents include: I. Minimize the speed of vehicles at potential collision points II. Separate movements and points of conflict by channelization, or in some situations, prohibit certain movements (and provide for hem at other intersections along the route) III. Control movements to reduce the possibility of conflict IV. Clearly define vehicle paths by use of pavement markings. ___ Traffic can be controlled at intersections by traffic control device such as: I. Regulatory Signs II. Traffic signals III. Roundabouts ___ Traffic signals improve safety and simplify decision making. They also:  I. Separate vehicle movements in time. This minimizes conflicts. II. Minimize delays at an intersection III. Enable vehicles from a side road to cross or enter the major road IV. Assist pedestrians in crossing the road ___ A conflict point occurs where two travel paths interact or cross. Safe intersection design uses the following principles: I. Minimizing the number of conflict points II. Minimizing the area of conflict III. Separating points of conflicts IV. Giving preference to major movements V. Minimizing relative speed of conflicting movements ___ The speed of vehicles through an intersection depends on: I. Alignment II. Road environment III. Traffic volume and composition IV. Traffic control devices ___ Low relative speed conditions at intersections can be obtained by: I. Choosing a layout where conflicting movements cross at angles less than or equal to 90 degrees II. Providing a layout or alignment that slows down approaching vehicles III. Providing deceleration lanes ___ Provision for turning lanes can generally be provided in the following ways: I. Shared turning and through lane II. Flaring and taper III. Separate lane for deceleration and storage ___ A traffic island is providing with this treatment to: I. Guide traffic into defined paths II. Separate through, turning and opposing traffic movements III. Give advance warning of the intersection to approaching drivers IV. Provide refuge for pedestrians V. Prohibit undesirable or unnecessary traffic movements ___ It is one of the safest type of intersection treatments. It consists of a circular island in the middle of an intersection and traffic moves around it in an anticlockwise direction. Roundabout ___ Many factors need to be taken into consideration when choosing the type of intersection to be provided at a given location. Roundabouts may be appropriate in the following situations: I. At intersections with high accident rates II. When physical control of speed is desirable III. When the flows on each approach are balanced and capacity analysis indicates that volumes can be managed IV. When the volume of the left turners is significant V. If traffic signals may be inefficient e.g. due to a large number of phases VI. For multi legged intersections ___ However, it must be recognized that drivers and riders are only human and will sometimes make mistakes and lose control of their vehicles. The reasons that they might lose control are many, for example: I. Excessive speed II. Fatigue or inattention III. Alcohol or drugs IV. Road condition ___ They are used to shield errant vehicles to shield errant vehicles from running into hazards that cannot be relocated or made more frangible. Roadside barriers ___ The warrant for the use of safety barriers can be established considering: I. Fore slope or back slope steepness and height II. Unforgiving hazards within the clear zone III. Water hazards within the clear zone ___ It can be defined as the combination of the likelihood and the consequence of a crash occurring. Risk ___ The likelihood of a crash occurring depends on various factors like I. Driver behavior (inattention, fatigue, risk taking) II. The quality of the road (surface, alignment etc) III. The vehicle (poorly maintained brakes, tires etc.) ___ If a crash does occur, the consequence of the crash depends on things like I. The speed of the vehicle II. The severity of roadside hazards III. The ability of the vehicle to protect the occupants (seatbelts, air bags, crumple zone, collapsible steering column, etc) ___ 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. Traffic Signs ___ Signs that inform road users of traffic laws and regulations which, if disregarded, will constitute an offense. Regulatory Signs ___ Signs that instruct road users to meet certain traffic rules requirements or road condition. Special Instruction SIgns ___ Warn road user of condition on or adjacent to the road that may be unexpected or hazardous. Warning Signs ___ Inform and advise road users of directions, distances, routes, the location of services for road users, and points of interest. Guide Signs ___ Warn or advise of temporary hazardous conditions that could endanger road users or the men and endanger road users or the men and equipment engaged on roadwork. Roadwork 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. Overhead Sign ___ 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. Barriers ___ Warning devices used to supplement other controls and devices necessary to alert motorists of construction and maintenance activities or obstructions in the roadway. Flashing Lamps ___ Light retro-reflecting devices mounted at the side of the roadway, in series, to indicate the roadway alignment. Delineators ___ 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 roadwat or rigidly attached for continued use. Traffic Cones ___ Roadwork devices consisting of pre-cast concrete sections, sandbag, and other which may be used to guide traffic at the construction site. Temporary CUrbing ___ Device used in place of rigid barrier posts or traffic cones with a minimum of 459mm by 50mm wide with alternate bands of contasting color as seen by approaching traffic for delineation of traffic. Flexible Post or Bollard ___ TO be effective, the road sign should meet the five basic requirements: I. Fullfill a need  II. Command attention III. Convey a clear, simple messafe IV. Command respect V. Give adequate time for proper response ___ Standard sign shape reserved exclusively for the STOP sign Occtagon ___ Standard sign shape is reserced for the GIVE WAY sign Equilateral triangle, with one point vertically downward ___ Standard sign shape mainly used for regulatory signs Circle symbol ___ Standard sign shape used for warning signs Equilateral triangle with one point vertically upward ___ Standard sign shape used for directional signs, ervice signs, road work signs, signs for special purposes, and supplementary plates for warnign signs Rectangle with long axis horizontal ___ Standard sign shape generally used for facility information signs, instruction signs, guide signs, and destinations of point of interest Rectangle with long axis vertical ___ Standard sign shape used only for pedestian and school crossing sign Pentagon, with point up ___ Standard color signs used as a background for STOP signs, as border color to GIVE WAT signs, warning signs and prohibitice signs in the regulatory type Red ___ Stancdard color signs used as legend color for signs having white, tellow, orange, fluoresent orange, fluoresent yellow green background and as chevron for hazard markers Black ___ Standard color signs used as background color for roadwork sign Yellow ___ Standard color for sign the background color for most signs and legends for some colored background White ___ Standard color for signs 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 Fluoresent yellow green ___ Standard color for signs used as background color for roadwork signs whose legends relate to personnel working Fluoresent orange ___ Standard color for signs used as background color for direction signs Green ___ Standard color for signs used as background color for service signs Blue ___ Standard color for signs reserved as background color for all tourist facility directional and informataion signs Brown ___ These are used to emphasize to the approaching driver a marked change in the direction of travel and the presence of an obstruction Hazard markers ___ These markers indicate to the approaching driver the direction to be followed if the marker appears in the driving path One-way hazard markers ___ Signs used to guide drivers through a change in horizontal alignment of the road Chevron Signs ___ These markers are used where it is necessary to delineate an exposedd obstruction on a traffic island nose at which traffic may pass to either side, THis sign can be used on a wide column of an overpass structure, or a median island separating the carriagewat with traffic proceeding in the same direction. Two-way hazard markers ___ These are used to delineate obstructions within or above the road Obstruction markers ___ These are used to mark the edge of the road formation. They assist the road users by indicating the alignment of the road ahead, especially at horizontal and vertical curves. Guide posts ___ These are small reflective panels or buttons mounted on guideposts or guard fence as an effective aid to delineate the roadwat for driving at night Delineators ___ Pavement markings shall onnly be applies and/or removed by the ___ or an authority to which these powers are delegated DPWH ___ These shall be uniform in design and application. As in the case with all other traffic control devices, it is imperative that markings be uniform so that they may be recognized and understoon instantly by all drivers Pavement markings ___ Longitunidal lines which are those laid in the direction of travel. These include: I. Center Line II. Lane line III. Double yellow line IV. ‘No-Passing’ zone markings V. Pavement edge line VI. Continuity lines VII. Transition line ___ Transvers lines which are laid accross the direction of travel. These include: I. Stop line II. Give way lines III. Pedestrian crossing markings IV. Roundabout holding lines ___ The color of pavement markings shall be white except for the alternatice uses of yellow as specified below: I. Double yellow no-passing lines II. Unbroken portion of no-passing lines III. Curb markings for prohibition of parking IV. On islands in line of traffic V. Bus and PUJ lanes VI. Keep Intersection Open markings ___ Red shall be used in: I. No Loading/Unloading Zone II. Fire lane zone ___ This color may be used in hazard markers to warn road users at locations where the protruding objects such as bridge piers, traffic islands and other permanent objects on or near the roadway. Black ___ It shall consist of line segments with equal lengths separated by uniform gaps. The speed of vehicles on the section of road or in the area in question should be taken into account in determining the lengths of the line strokes and of gaps between them. Broken line ___ It is used where crossing of the line is either discouraged or prohibited. It is generally used to replace or supplement a broken line where required e.e., barrier lines, and center lines. These lines may be either yellow or white depending whether or not crossing the line is legally prohibited Solid unbroken line ___ It is used to separate opposite traffic movements of an undivided roadway and is generally placed centrally on all roads and bridges 6.0 m or more in width. Under some circumstances this line may be places off-center (e.g., where an extra uphill traffic lane is provided or parking on one side of the road only) Center line ___ It is used to separate adjacent lanes of traffic moving in the same direction Lane line ___ Lane lines must be continued on the following cases: I. Across signalized intersections. However, lane lines of low priority road must be discontinued at the intersection II. Across side street entrances unless the street is one-way street (goin in only) III. Past the start of the taper at which a multi-lane road narrows down ___ As a guide, lane lines should be used in the following cases: I. Where the road is wide enough for two or more lanes of traffic in one direction with a two way annual average daily traffic (AADT) of 8000 or more (depending on whether parking is permitted) II. At approaches to widened or signalized intersection III. On divided roads ___ A lane width defined by lane lines may only be reduced to ___ in urban areas 2.75m ___ Barrier lines may consist of either: I. Two unbroken yellow lines II. Single unbroken yellow linne III. Single yellow line with a broken white line ___ The following are the cases where barrier lines should be used: I. As center lines on approaches to signalized intersections II. As center lines of multi-lane roads where overtaking must be prohibited, because of sight restrictions III. ‘No-Passing’ zones where there is a restricted sight distance due to horizontal or vertical curves IV. As center lines on approaches to railway crossings ___ It is used to delineate the edge of the traveled way to distinguish it from the shoulder area. It should be a solid white line between 100mm and 200mm wide. Studs, or raised pavement markers may be used in conjunction with edge lines where there are paved shoulders. Edge line ___ The purpose of installing edge lines generally based on the following:  I. To discourage travel on road shoulders II. To make driving safer and more assured, particularly at night and during inclement weather by providing a continuous guide for the driver III. To act as a guide past objects which are close to the edge of pavement and which constitute a hazard IV. To prevent parking at or near intersections ___ It is used to indicate that portion of a carriageway assigned to through traffic. It is intended to be crossed by traffic turning at an intersection, or entering or leaving an auxiliary lane at its start or finish Continuity line ___ These are used to guide traffic safely past obstructions on roadways such as islands, median strips, bridge piers or indicate changes in the width of the traveled portion of the roadway and an increase or reduction in traffic lanes Transition lines ___ Transverse lines may be classified into the following types: I. Stop lines II. Give way lines III. Pedestrian crossing markings IV. Roundabout holding lines ___ These are often used to guide traffic into the right turning lanes separated by an island, such as a corner island at a signalized intersection. Chevron markings ___ These are placed on sealed shoulders or other sealed portion of the road where traffic is not desired. Such markings are of the same bar width as other diagonal markings. The spacing between bars is generally 6m. Diagonal markings ___ It is a type of thermoplastic ane marking design to aid and provide motorist with visual, audio and motion warnings on the road. These are highly visible humming sound and ample bumpy ride to the motorists when ran over. It promotes better traffic safety because it stimulates more the human senses while driving. Rumble strips ___ Messages when painted on pavement should be limited to __________ Three words or less ___ These are used for lane use control. White in color, they are generally 5m in length on urban roads and 7.4m on high-speed roads. The sizes and arrow heads. Pavement arrows ___ Lengths of letters or numerals used on messages painted on pavement in urban areas 2.5m ___ Lengths of letters or numerals used on messages painted on pavement on high-speed highways 5m