ch3 ITE 2-2.ppt

1、CH 3,TRANSPORTATION INFRASTRUCTURE,CHAPTER OUTLINE,KEY TERMS:,TCD-traffic control device 交通控制设施: be defined as all signs, signals, markings, and other devices used to regulate, warn, or guide road users, placed on, over, or adjacent to a street, highway, pedestrian facility, or bikeway by authority

2、of a public body or official having jurisdiction.,SPECIAL WORDS:,progressively 日益增多地 two-lane 双车道 free-flow 自由流的 access 入口 egress 出口 ramp 斜坡，坡道,median strip 隔离带 terrain 地形 volume-to-capacity ratio 容量能力比 pc/mi/ln-passenger cars per mile per lane 车辆密度单位：车辆数/每公里/每车道 curvature 弯曲，曲率 Intersection 交叉口 ASS

3、HTO-American Association of State Highway and Transportation Officials 美国国家公路与运输协会标准,Roundabout 道路交叉处的环形路, 迂回路线 safe stopping distance安全停车距离 subgrade 路基,first-come, first-served 先到先服务 Traffic marking 交通标线 Traffic sign 交通标志 Traffic signal 交通信号,Traffic control devices is defined as the media by which

4、traffic engineers communicate with road users, and functioned as the conveyor of traffic law and regulations.,Definition,Traffic control devices strive to provide safe and efficient functioning of intersections by separating conflicting vehicle streams in time.,Function,Be needed,Requirements of TCD

5、:,Command attention,Convey a clear, simple message,Command respect,Be placed to get the proper response from the driver,Categories of Traffic Control Devices,Traffic Markings,(1) Three Sorts of Traffic Markings:,杭州首条彩色斑马线亮相 有望遏制交通事故,五花八门的交通工程设施,减速设施,京平高速：限速标线,立体斑马线,彩色防滑标线,紧急避险车道.,隧道进出口视觉过渡措施标线,这样的标志

6、牌你见过吗,十大最雷人交通标志,Colors,Yellow markings separate traffic traveling in opposite directions. White markings separate traffic traveling in the same direction, and are used for all transverse markings. Red markings delineate roadways that shall not be entered or used by the viewer of the marking.,Blue ma

7、rkings are used to delineate parking spaces reserved for persons with disabilities. Black markings are used in conjunction with other markings on light pavements. To emphasize the pattern of the line, gaps between yellow or white markings are filled in with black to provide contrast and easier visib

8、ility.,Patterns,Crosswalk Markings,Points of pedestrian concentration,All intersections at which “substantial” conflict between vehicles and pedestrian exists,Locations where pedestrians might not otherwise recognize the proper place and/or path cross,Parking Space Markings,Parking space markings ar

9、e not purely transverse, always optional and used to encourage efficient use of parking spaces.,Parking spaces along the curbline of a street or in a parking lot are delineated by white lines of various patterns.,Delineators,Delineators are reflective devices mounted at a 4-ft height on the side(s)

10、of a roadway to help denote its alignment, which are also vulgarly called cats eyes, and are particularly useful during inclement weather.,Definition,Color,When used on the right side of the road-way, delineators are white,when used on the left side of the roadway, delineators are yellow,The back of

11、 delineators may have red reflectors to indicate wrong-way travel on a one-direction roadway,Delineators are mandated on the right side of freeways and expressways and on at least one side of interchange ramps.,Location,Delineators may also be omitted where there is continuous roadway lighting betwe

12、en interchanges.,3.5.3 Traffic Signs,(1) Regulatory Signs,Regulatory signs are used to impose legal restrictions applicable to particular locations. They inform drivers of certain laws and regulations, the violation of which constitutes a misdemeanor.,right-of-way signs, the most common being stop a

13、nd yield signs speed signs movement signs, such as turning or one-way signs parking signs,Regulatory signs shall be used to inform road users of selected traffic laws or regulations and indicate the applicability of the legal requirements. Regulatory signs shall be installed at or near where the reg

14、ulations apply.,Examples,Except for some special signs, such as the STOP and YIELD sign, most regulatory signs are rectangular, with the long dimension vertical. Some regulatory signs are square.,Shape,To be effective, a speed limit must be communicated to the driver and should be sufficiently enfor

15、ced to engender general observance.,Speed limits,Turn prohibition sign,Lane-use control signs are used wherever a given movement or movements are restricted and/or prohibited from designated lanes, including left-turn- and right-turn-only lanes, two-way left-turn lanes on arterials, and reversible l

16、anes.,Lane-use control sign,Where a sign is indicating a prohibition, red legend on a white background is used. Where a sign is indicating a permissive situation, green legend on a white background is used.,（2）Warning Signs,Warning signs are used to call attention to hazardous conditions, actual or

17、potential, that would otherwise not be readily apparent.,Most warning signs are diamond-shaped, with black lettering or symbols on a yellow background. A pennant shape is used for the “No Passing Zone” sign, used in conjunction with passing restrictions on two- lane, two-way rural highways. A rectan

18、gular shape is used for some arrow indications. A circular shape is used for railroad crossing warnings.,Shape,When used, warning signs must be placed far enough in advance of the hazard to allow drivers adequate time to perform the required adjustments.,Usage,Warning signs are used to inform driver

19、s of a variety of potentially hazardous circumstances, including:,Changes in horizontal alignment Intersections Advance warning of control devices Converging traffic lanes Narrow roadways Changes in highway design,Grades Roadway surface conditions Railroad crossings Entrances and crossings Miscellan

20、eous,Changes in horizontal alignment,Intersections,Advance warning of control devices,Converging traffic lanes,Narrow roadways,Roadway surface conditions,Railroad crossings,Entrances and crossings,Miscellaneous,(3) Guide Signs,Guide or informational signs provide directions to drivers and to various

21、 destinations. These are placed far enough ahead of intersections and interchanges to allow adequate time for drivers to make their routing decisions.,Guide signs provide information to road users concerning destinations, available services, and historical/recreational facilities.,Example,INDIANA 9,

22、Guide signs are rectangular, with the long dimension horizontal, and have white lettering and borders the background varies by the type of information contained on the sign.,Shape and color,Directional or destination information is provided by signs with a green background; information on services i

23、s provided by signs with a blue background; cultural, historical, and/or recreational information is provided by signs with a brown background.,(4) Directional Signs,Directional signs on high-speed highways are used at interchanges associated with freeways.,Destination signs used on conventional roa

24、dways are to indicate the distance to critical destinations along the route and to mark key intersections or interchanges. On conventional roads, destination signs use an all-capital white legend on a green background.,Destination sign,Where interchanges are widely separated, advance guide signs can

25、 be placed as much as five or more miles from the interchange and may be repeated several times as the interchange is approached.,Advance guide sign,Advance signing usually gives information only concerning the next interchange, to avoid confusion caused by overlapping signing sequences.,3.5.4 Traff

26、ic Signals,All power-operated devices (except signs) for regulating, directing, or warning motorists or pedestrians are classified as traffic signals.,Purposes,To improve overall safety,With appropriate physical designs, control measures, and signal timing, the capacity of critical intersection move

27、ments is increased. The frequency and severity of accidents is reduced for certain types of crashes, including right-angle, turn, and pedestrian accidents.,Benefits,When properly coordinated, signals can provide for nearly continuous movement of through traffic along an arterial at a designated spee

28、d under favorable traffic conditions. They provide for interruptions in heavy traffic streams to permit crossing vehicular and pedestrian traffic to safely cross.,Varieties of Traffic Signals,Traffic control signals Pedestrian signals Emergency vehicle traffic control signals Traffic control signals

29、 for one-lane, two-way facilities,Types,Traffic control signals for freeway entrance ramps Traffic control signals for moveable bridges Lane-use control signals Flashing beacons In-roadway lights,A traffic control signal shall be operated in either a steady-state (stop and go) mode or a flashing mod

30、e at all times.,Standards,STOP signs shall not be used in conjunction with any traffic control signal operation except in either of the two following cases:,Signal Indications,Green ball Yellow ball Red ball Flashing ball Arrow indications,A steady green circular indication allows vehicular traffic

31、facing the ball to enter the intersection to travel straight through the intersection or to turn right or left, except when prohibited by lane-use controls or physical design. In the absence of pedestrian signals, pedestrians may proceed to cross the roadway within any legally marked or unmarked cro

32、sswalk.,Green ball,The steady yellow circular indication is a transition between the Green Ball and the Red Ball indication. It warns drivers that the related green movement is being terminated or that a red indication will immediately follow.,Yellow ball,The steady red circular indication requires

33、all traffic (vehicular and pedestrian) facing it to stop at the STOP line, crosswalk line (if no STOP line exists), or at the conflicting pedestrian path (if no crosswalk or STOP line exists).,Red ball,A flashing “yellow” allows traffic to proceed with caution through the intersection. A flashing “r

34、ed” has the same meaning as a STOP sign - the driver may proceed with caution after coming to a complete stop.,Flashing ball,A green left-turn arrow is only used to indicate a protected left turn. A green right-turn arrow is shown only when there are no pedestrians legally in the conflicting crosswa

35、lk.,Arrow indications,Yellow arrows warn drivers that the green arrow is about to terminate. A “permitted” left turn is made against an opposing vehicular flow. A “permitted” right turn is made against a conflicting pedestrian flow.,Thank you,The end of CH3,QUESTIONS,How does traffic infrastructure

36、define? What aspects does a highway system include? How to apprehend the meaning and function of traffic infrastructure? How many types of travel movements are there in a typical trip? What kinds of alleviation techniques may be applied to reduce problems on two-lane highways?,QUESTIONS,What are the

37、 main elements to define the geometry of a highway section? What is an intersection? How to understand the essentiality of intersections? How does a railroad system be composed? And what is the function of rail tracks? What are the main contents included in an air transportation system? Is the access to the airport important for air transportation? Why, or why not?,QUESTIONS,Is the term ha