Transportation Engineering PDF

Summary

This document discusses transportation engineering, including topics on traffic engineering, the transportation planning process, and travel demand modeling. It provides definitions and explanations for various concepts.

Full Transcript

1. Application of technology and scientific principles to the 1. Transportation Engineering planning, functional design, operation and management of facilities for any mode of transportation in order to provide for the safe, rapid, comfortable, convenient, economical and environmentally compatible...

1. Application of technology and scientific principles to the 1. Transportation Engineering planning, functional design, operation and management of facilities for any mode of transportation in order to provide for the safe, rapid, comfortable, convenient, economical and environmentally compatible movement of people and goods 2. A phase of transportation engineering which deals with 2. Traffic Engineering planning, geometric design and traffic operations of roads, streets and highways, their networks, terminals, abutting lands and relationships with other modes of transportation. 3. The traditional transportation planning process 3. Comprehensive planning process 4.It is an ongoing process which seek to assess the short 4. Transportation planning process and long range transportation problems of a region and to develop, evaluate, select and implement plans and strategies for solving these problems. 5. this is the interaction of 2 basic systems which are : 5. transportation system (origins, destinations, volume of people and goods ) activity system ( land uses, population, social and economic activities) 6. It describes the relationships between trip making and 6. Travel demand modeling the regions pattern of population, land use and economic activities. 7. Characteristics of traffic flows on the highway system 7. Drivers, vehicles ad roadway itself are the results of complex interactions between these basic elements 8. The perception of and reaction to, cues and stimuli 8. Perception, identification, emotion and reaction or encountered by the driver of a vehicle involves in the volition following distinct actions 9. 4 basic phases of traditional approach to travel 9. demand modeling Trip generation Trip distribution Mode choice Traffic assignment 10. The period of time when the driver recognizes an 10. Perception and reaction time object or a hazard on the roadway to the time the driver actually applies the brakes 11. The distance needed to bring the vehicle to a 11. Braking distance complete stop after the brakes have been applied 12. The shortest distance sufficient for a vehicle to turn 12. Passing sight distance out of a traffic lane, pass another vehicle, and then turn back to the same lane safely and comfortably without interfering with the overtaken vehicle or an incoming vehicle traveling at the design speed should it come into view after the passing maneuver is started. 13. The sum of the braking distance and the perception 13. Stopping sight distance and reaction distance 14. The amount of time required for a driver to detect 14. Detection and recognition time and recognize that an object or hazard is being approached 15. The amount of time for the driver to decide on the 15. Decision and response initiation time proper maneuver to be taken and to initiate the required action 16. The time required to accomplish a vehicle maneuver 16. Maneuver time 17. The distance required for a driver to detect an 17. Decision sight distance unexpected object, in formation source ( traffic signal ) or hazard in the roadway and to recognize the hazard, select an appropriate speed and path, and initiate and complete the required safety maneuver 18. 18. Sight distance The distance at which a driver can see an object lying in the roadway ahead. 19. sight distance should _____or_____ the stopping 19. equal, exceed sight distance 20. 20. Non-passing sight distance The length between a vehicle as it enters a crest curve ( vertical parabolic ) and the farthest distance visible to a driver to the top of the object. 21. In Non-passing sight distance , It is typically assumed 21. that the height of eye is ______above the roadway 3.75 ft surface and the farthest distance visible is at an elevation 6 inches of ______above the roadway 22.When a vehicle moves in a circular path it is pulled 22. Side friction factor radially outward by a centrifugal force. 23. Other name for Side friction factor (3) 23. lateral ratio ornering ratio unbalanced centrifugal ratio 24.What is Travel Demand Modelling? (4) 24. Most important aspect Modeling Transport demand and supply Equilibrium Traditional 4 step demand modeling 25. Simplified, complex enough to reproduce key 25. Transport Modeling relationships of the reality. Physical Types : (3) Symbolic Mathematical 26. Make physical representation of the reality 26. Physical E.g. model aircrafts used in wind tunnel 27. Complex relations could be represented with the help 27. Symbolic of symbols. E.g. drawing time-space diagram of vehicle movement 28.Most common type when with the help of variables, 28. Mathematical parameters, and equations one could represent highly complex relations. E.g. Newton’s equations of motion or Einstein’s Equations 29. Things to take note on Transportation modeling: 29. No model is a perfect representation of the reality Important objective is that models seek to isolate key relationships, and not to replicate the entire structure It is the study of the behavior of individuals in making decisions regarding the provision and use of transport Evolved from many disciplines like economics, psychology, geography, sociology, and statistics. 30. 30.Transport demand and supply Associated supply of transport infrastructure Transport demand is derived demand and not a need in itself People travel not for the sake of travel, but to practice in activities in different locations 31. 31. Transport demand is a _____demand, and not a DERIVED need in itself practice in activities People travel not for the sake of travel, but to _________in different locations 32. The concept of equilibrium is _____to the supply- 32. central demand analysis 33. The ________defines the supply function as giving 33. classical approach the quantity T which would be produced, given a market price C. 34. aims to establish the spatial distribution of travel 34. TRAVEL DEMAND MODELING explicitly by means of an appropriate system of zones 35. The base decisions on travel demand modeling (3) 35. choice of destination, choice of the mode choice of the route 36. Classical transport model a.k.a. FOURSTAGE model 36. ( FSM ) : Sequence of four sub models (4) Trip generation Trip distribution Modal split Figepstrip assignment 37. 38. TRIP GENERATION Define study area Divide study area into number of zones 38. Database also include________, economic activity 38. like________, ______, _______, and ______of each zone the current ( base year ) levels of population employment shopping space educational leisure facilities 39. 39. TRIP DISTRIBUTION Evolve the trip assignment Use the data to estimate the total number of trips generated and attracted by each zone Allocate these trips from each zone to various other destination zones in the study area using trip distribution models The output of the model is a trip matrix which denote the trips from each zones to every other zones. 40. 40. MODAL SPLIT Trips are allocated to different modes based on the modal attributes. Essentially slicing the trip matrix for various modes to generate a mode specific trip matrix 41. 41. DATA COLLECTION The 4 stage modeling An important tool for forecasting future demand and performance of a transportation system, was developed for evaluating large-scale infrastructure projects. It is less suitable for the management and control of existing software. These models are applied to large systems, they require information about travelers of the area influenced by the system. Data requirement is very high, and may take years for the data collection, data analysis, and model development. Meticulous planning and systematic approach are needed for accurate data collection and processing. 42. 42. Survey design Not easy Requires considerable experience, skill, and sound understanding of the study area Purpose of the study and details of the modeling approaches Practical considerations like availability of time and money 43. Categories under Survey Design : Information needed 43. Travel surveys Land-use inventory Network data 44. _____ _____should be defined such that majority of 44. Study area trips have their origin and destination in the study area and should be bigger than the area-of interest covering the transportation project 45. 45. Land-use inventory Data on the housing density at residential zones Establishments at commercial and industrial zones Useful for trip generation models 46. 46. Network data Data on the transport network and existing inventories Includes road network, traffic signals, junctions etc. Service inventories include data on public and private transport networks Use for model calibration, especially for the assignment models 47. Once study area is defined, it is then divided into a 47. ZONES number of small units called ________or_____ 48. It is the zone with in the study area 48. INTERNAL ZONES 49. Zones are in modeling as if all their attributes and 49. ZONE CENTROID properties were concentrated in a single point called the ______ ______ 50. The intersection from outside world is normally 50. EXTERNAL ZONES represented through _______ ______ 51. Both centroid and centroid connectors are ______and 51. notional it is assumed that all people have same ____ ____from travel cost the centroid to the nearest transport facility which is the average ______for a zone 52. How to select zones 52. Zones should match other administrative divisions, particularly census zones Zones should have homogenous characteristic, especially in land use, population etc. Zone boundaries should match cordon and screen lines, but should not match major roads Zones should be as smaller in size as possible so that the error in aggregation caused by the assumption that all activities are concentrated at the zone centroids is minimum 53. 53. Household data To understand the behavior and factors affecting the travel, one has got the origin of travel when the decision for travel is made It is where people live as family which is the household Considered as the most basic and authentic information about the travel pattern of a city 54 Household data : Survey administration methods : 54. Telephonic Mail back Face-to-face 55. Enumerator may use telephone to fix an 55. Telephonic appointment and then conduct detailed telephonic interview 56. 56. Mail back Enumerator drops the questionnaire to the respondent and asks them to fill the details and mail them back with required information Care should be taken to design the questionnaire so that it is self explanatory 57. 57. Face-to-face Enumerator visits the home of the respondent and asks them questions and fills up the questionnaire by himself. This is not a very socially acceptable method in the developed countries, and thee are treated as intrusion to privacy However, in many developed countries, especially with less educated people, this is the most effective method 58. The area where two or more roads come together 58. Intersection 59. The roads approaching the intersection 59. Legs of the intersection 60. The number of cars that need to be stored during 60. Capacity peak hours in the design of auxiliary lanes 61. The intersection with auxiliary lanes 61. Flared intersection 62. The identification of streets and highways in terms of 62. Functional classification degree to which the competing and conflicting functions of movement and access are to be served. 63. The number of vehicles that pass appoint on a 63. Traffic volume highway during a specified time interval 64. Average 24 hour traffic volume at a specified location 64. Average annual daily traffic ( AADT ) over a full year (365days) 65. Average 24 hour traffic volume occurring on 65. Average annual weekly traffic ( AAWT ) weekdays at a specific location over a full year 66. Basically an estimate of AADT based on a time period 66. Average daily traffic ( ADT ) less than a full year 67. An estimate of AAWT based on a period less than a 67. Average weekly traffic ( AWT ) year 68. Traffic volumes for periods of time less than one hour 68. Equivalent hourly rates of flow ( typically measured in 15 mins. Increments ) 69. The relationship between hourly volume and the 69. Peak hour factor maximum 15 minute rate of flow within the hour 70. In design, peak hourly volumes are sometimes 70. DDHV = AADT x K x D estimated from daily volumes 71. The average speed of all vehicles passing a point on 71. Time mean speed the highway over a given time period 72. The average speed obtained by measuring the 72. Space mean speed instantaneous speeds of all vehicles on a section of roadway 73. A method of trip distribution involving the use of 73. Growth factor method existing volumes of interzonal traffic to measure friction prior to expanding the volume between two points in proportion to an inter-actance facto 74. The hourly volume of traffic divided by the average 74. Density speed 75. A guide in determining upper speed limits 75. 85th percentile value 76. The maximum number of passenger cars that can 76. Basic capacity pass a given point per hour under the most nearly ideal roadway and traffic conditions 77. Difference between the observed speed and the 77. Delay rate standard speed for a particular type of road 78. A diamond highway interchange in which the 78. Bridge rotary intersecting conflicts are changed to weaving conflicts 79. Street which serves internal traffic movements within 79. Collector street an area and connects this area with major arterials 80. A method of signal timing whose purpose is to first 80. Advance green clear the vehicles desiring to turn left at an intersection 81. A signal system in which the faces which control a 81. Simple progression given street will be green according to a time schedule which will permit continuous operation of vehicles as is possible along the street 82. The allocation of traffic flows among routes available 82. Traffic assignment 83. The distance between vehicles in a traffic stream 83. Spacing or space headway 84.Dark brown to black cementitious materials in which 84. Asphalt the predominating constituents are bituments which occur in nature or are obtained in petroleum processing 85. A plaster coat or coats applied prior to application of 85. Base coat the finish coat 86. Complete application of base coat plaster 86. Brown out 87. A man who is assisting a crane driver by signaling to 87. Banksman him when he is to raise, lower of swing his load 88. The penetration test on asphalt cement is used to 88. Hardness determine its ______ 89. The system of roads available within a particular 89. Road net locality or area is known as ______ 90. A pavement that has a wearing surface of bituminous 90. Flexible pavement material such as asphalt and its strength depends upon the bearing capacity of subgrade 91 Curves on highways must be super elevated in order 91. Centrifugal force to counteract the effect of ___ 92. A very thin surface treatment of bituminous material 92. Seal coat which is applied as a final step in the construction of certain bituminous wearing surfaces of roads 93. The single application of liquid bituminous material 93. Prime coat to a previously prepared and untreated road base, such as earth, gravel, stabilized soil, or water bound macadam base courses 94. The single initial application of bituminous material 94. Tack coat to an existing bituminous , Portland cement concrete, or block surface 95. The graded portion of a highway within top and side 95. Road bed slopes, prepared as a foundation for the pavement structures and shoulders 96. The ratio of the load of wheel to the contact area or 96. Contact pressure area of imprint as used in the design of pavement 97. The ratio of contact pressure to tire pressure as used 97. Rigidity factor in pavement design 98. The numerical difference between the liquid limit 98. Plasticity index and the plastic limit 99. The soil base over which the other layers of the 99. Sub-grade pavement is constructed 100. The crossing of two or more traffic streams 100. Weaving traveling in the same general direction along a significant path of highway without the aid of traffic signal 101. The percentages of water at which the soil changes 101. Plastic limit from plastic to semi-solid state. It is the water content expressed as a percentage of the weight of oven dry soil at the boundary between plastic and semi-solid states of consistency. 102. When a sample of soil-water changes from viscous 102. Liquid limit to plastic stage, the moisture content causing this change is called ____ 103. The moisture content beyond which any reduction 103. Shrinkage limit in the moisture content will not cause further decrease in volume 104 The ratio expressed as a percentage of the natural 104. Liquidity index water content of a soil minus its plastic limit to its plasticity index 105. The load per unit at which an unconfined cylindrical 105. Unconfined compression test specimen of soil will fail in a simple compression test at a constant rate of strain 106. The ratio of the force per unit area required to 106. California bearing ratio penetrate a soil mass with a standard circular piston at the rate of 1.22 mm/minute to that required for corresponding penetration of a standard material 107. A complex organic material occurring naturally or 107. Bitumen can be prepared artificially by fractional distillation of crude petroleum at successively higher temperatures 108. Bitumen grade is usually expressed as 80/100 , what 108. Penetration value is the meaning of number 80 109. Viscous liquid obtained when natural organic 109. Tar materials such as wood, or coal are destructively distilled in the absence of air 110. California bearing ratio (CBR) test on soil measures 110. Resistance to penetration the ____ 111 Sieve analysis of soil for coarse grained particles and 111 Grain size distribution sedimentation analysis for soil fines 112 The grinding action of and impact of tires on road 112 Abrassion aggregates 113 The fracture of stone by repeated falling of a 113 Impact hammer on it gives resistance to 114. The strength test for aggregates used in a mixture 114 Crushing of pavement materials is measured by its resistance to ____ 115. Classification of pavements according to their 115 Flexible pavements and rigid pavements structural behavior 116. A road made of coarse aggregate mechanically 116. Water bound macadam road interlocked by rolling and bonded together with screening dust 117. An application of hot bitumen material given to 117. Tack coat the old surface to provide adhesion to the old and new road surfaces 118. A layer of stone chippings coat laid over a hot to 118. Prime coat make the surface water-proof 119. A very thin surface applied over a bituminous 119. Seal coat pavement to make it impervious 120 The application of one or two layers of bituminous 120. Surface dressing material over a prepared based each layer covered with an application of cover material and rolled 121 The layered structure placed over a soil sub-grade 121 Pavement for forming a road 122 A pavement which has negligible flexural strength 122 Flexible pavement 123 A pavement which depends on its flexural strength 123 Rigid pavement 124 The layer of natural soil over which the pavement of 124 Sub grade a road is laid 125 The layer in a road pavement which provides 125 Wearing course resistance to wear and tear due to traffic 126 The part of the road structure which is immediately 126. Sub base above the subgrade and composed of stone boulders or superior soil 127 The top surface of a road structure ; the component 127 Base of the road structure which receives the traffic load and transfers it to the subgrade 128 The layer of the pavement which carries the load 128 Sub-grade from the road 129 Traffic signs which are used to inform road users 129 Regulatory or mandatory signs certain rules and regulations which have to be observed for safe and free flow of traffic 130 Traffic signs which are used to caution the drivers 130 Warning or cautionary signs about certain hazardous conditions ahead. These warn the driver so that he can take the desired precaution. 131 Traffic signs which are provided for route 131 Informatory and guiding signs identification, direction to travelers and such other information a traveler requires in order to reach his destination. 132 Traffic signals which are located on the left hand side 132 Primary signal of the road as near the stop line as possible 133 An additional traffic signal which is placed on the 133 Secondary signal departure side of the intersection on the right side 134 Stopping or go signal will be given to a particular 134 Phase stream each time. Thus, in each cycle, different streams will have different times for being given green / red, based on the volume. The number of such operations in a cycle containing red-yellow-green 135 Type of road signals which are set to repeat a cycle 135 Fixed time signals of sequence and phase of the cycle at a regular time intervals. These signals are designed for peak time traffic requirements. However, they cause delay during off peak hours. 136 Type of road signals which are designed so that the 136 Traffic actuated signals phase and cycle can be changed according to traffic demand. A policeman observes the flow of traffic and operates these signals suitably. These signals can be very expensive. 137 Type of road signals which are installed on main 137 Flashing signals roads and cross roads. A red signal is provided on the cross road to warn the driver to stop and proceed. A yellow signal installed on the main road warns the driver to slow down. 138 The traffic which measures the proportion of 138 Traffic volume study different types of traffic and establish relative importance of roads 139 When two roads cross each other 139 Intersection 140 The number of vehicles crossing a given cross- 140 Traffic volume section of road during unit time 141 The instantaneous speed of any vehicle at any 141 Spot speed specified point 142 Average speed of the vehicle over a distance when 142 Journey speed delays are taken into account 143 The delays due to signals, stop signs and railroad 143 Fixed delays crossing 144 Delays due to congestion of traffic lack of capacity, 145 Operational delays pedestrians, parking and unparking vehicles 146 The amount, duration, and causes of delay in the 146 Speed and delay study traffic stream as well as to find the time spent to travel along a particular route 147 Major roads cross each other at different elevations 147 Grade separated intersection 148 Major roads that cross each other at the same 148 At grade intersection elevations 149 When the major highway is taken above by raising 149 Over pass its profile above the general ground level by embankment and an overbridge across another highway 150 When the major highway is taken by depressing it 150 underpass below the ground level to cross another road by means of an underbridge

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