Highway and Railway Design Criteria PDF

Design Criteria For Highways And Railways HIGHWAY DESIGN The goal in Highway Design is to provide safe roads for all road users, and not just those in motor vehicles. The principle that “man is the reference standard” implies that roads must be adapted to the limitations of human capacity...

Design Criteria For Highways And Railways HIGHWAY DESIGN The goal in Highway Design is to provide safe roads for all road users, and not just those in motor vehicles. The principle that “man is the reference standard” implies that roads must be adapted to the limitations of human capacity, which leads to what is called the “Safe Systems Approach.”  SAFE SYSTEMS APPROACH The safe systems approach emphasizes that some degree of roadway user error will always occur, and that such errors should not result in a fatality or serious injury. In the safe system approach, the primary criterion is the safety of all road users, including pedestrians and bicyclists that are more vulnerable to injury and death when hit by a vehicle. This approach encourages the following in the design of roadways: a. Simple, self-explaining roads b. Designing roads that encourage/enforce safe speeds c. Forgiving roadsides WORLD BANK’S SUSTAINABLE SAFE ROAD DESIGN MANUAL Functionality – developing a hierarchy of mono-functional roads (e.g. truck, distributor and access. Homogeneity – avoiding differences in speed, direction of travel, and mass of vehicles Predictability – ensuring that roads are easy to understand and there are not nasty surprises The characteristics listed below are the controls in optimizing or improving the design of the various highway and street functional classes. Human Factors and Driver Performance Design Vehicles Design Volume Design Speed Physical Elements Classification of Highway Accident Information HUMAN FACTORS AND DRIVER PERFORMANCE The role of human factors research is to provide an understanding of how drivers perform as a system component in the safe operation of vehicles. This role recognizes that driver performance is influenced by many environmental, psychological, and vehicle design factors. The focus of the research is to determine which aspects of vehicle design should be modified to improve driver performance and reduce unsafe behaviors. An additional focus is to evaluate driver's capabilities to benefit from existing or new in-vehicle technologies. The research supports Federal Motor Vehicle Safety Standards, safety defects investigations, consumer information, and advancement of knowledge about driver behaviors and performance that can be applied to development of vehicle technologies that are compatible with driver capabilities and limitations -The suitability of a design rests as much on how effectively drivers are able to use the highway as on any other criteria. Considerations include: Driver tasks that include vehicle control (such as simultaneous multiple tasks and reaction time), guidance (such as road following, lane placement, car following, passing maneuvers and response to traffic control devices) and navigation. Use of the facility by older drivers and older pedestrians. Speed.  TRAFFIC SIGNS Turn left No left No motor No Two way Bend to left ahead turn vehicles overtaking traffic Road Turn right Hump Roundabout No right Crossroads work ahead turn ahead Stop and No Merge Parking uneven Slippery give way Parking Road Road Properly designed highways that provide positive guidance to drivers can operate at a high level of efficiency and with relatively few crashes. The World Health Organization recorded 1.35 million people died due to road traffic crashes. More than 90% of this recorded fatal road crashes occur in low-and middle-income countries. More so, 2019 statistics showed that the leading cause of death for children and young-adults aged 5 to 29 years is road traffic injuries (WHO). The organization tackles road safety through Decade of Action for Road Safety 2011-2020. In the Philippines, as of 2018 data, there are a total of 116,906 incidents of road traffic crashes in Metro Manila alone. On average there were 334 reported accidents per day with one resulting in fatality, 56 being non-fatal and 276 leading to damages to property (topgear.com). This leads to the Philippine Road Safety Action Plan 2017-2022, a program developed by the Department of Transportation adopting a vision of zero road traffic death, with an interim target to reduce road death rate by at least 20% by 2022. The interventions are organized according to the Action Plan of the Decade of Action for Road Safety 2011-2020, focusing on the following: (1) road safety management, (2) safe roads and mobility; (3) safe vehicles; (4) safe road users; and (5) post-crash care.  Design Design Vehicles Vehicles and and Turning Turning Radii Radii Design vehicles are selected motor vehicles with the weight, dimensions, and operating characteristics used to establish highway design controls for accommodating vehicles of designated classes. For purposes of geometric design, each design vehicle has larger physical dimensions and a larger minimum turning radius than most vehicles in its class. The design of an intersection is significantly affected by the type of design vehicle, including horizontal and vertical alignments, lane widths, turning radii, intersection sight distance, storage length of auxiliary lanes, and acceleration and deceleration lengths on auxiliary lanes. Four general classes of vehicles have been established, namely, passenger cars, buses, trucks, and recreational vehicles. The passenger car class includes, sedans, pick-up trucks, SUVs, minivans, and full-size vans. Design Design Vehicles Vehicles and and Turning Turning Radii Radii 4.2 to 4. 9 meters 5 meters Design Design Vehicles Vehicles and and Turning Turning Radii Radii Buses include inter-city (motor coaches), city transit, school, and articulated buses. 8,749 mm long, 2,500 mm wide, and 3,310 mm high Design Design Vehicles Vehicles and and Turning Turning Radii Radii Recreational vehicle CHOICE OF DESIGN VEHICLE The vehicle which occurs with considerable frequency is often selected as the design vehicle. The largest of all the several design vehicles are usually accommodated in the design of freeways, subject to state laws on permitted vehicles MINIMUM MINIMUM TURNING TURNING PATHS PATHS OF OF DESIGN DESIGN VEHICLE VEHICLE DEFINITIONS Turning radius The circular arc formed by the turning path radius of the front outside tire of vehicle. This radius is also described by vehicle manufacturers as the “turning curb radius” Centerline Turning Radius (CTR) The turning radius of the centerline of the front axle of vehicle. Turning radius Steering angle TheThecircular arc formed by the turning path radius of the front outside tire of vehicle. This radius is also described by maximum angle of turn built into the steering mechanism of the front wheels of a vehicle. The maximum angle controls the minimum turning radius of the vehicle. vehicle manufacturers as the “turning curb radius” Curb to Curb Turning Radius Centerline Radius of theTurning Radius smallest circle around (CTR) which the vehicle's tires can turn. Wall to Wall Turning Radius The turning radius of the centerline of the front axle of vehicle. Radius of the smallest circle around which the vehicle's tires can turn. This measures takes into account any front overhang due to chassis , bumper extensions and or aerial devices. Steering angle Off tracking TheThemaximum angle difference in the paths of turn of the frontbuilt into and rear theof steering wheels mechanism a tractor/ semitrailer of the as it negotiates front a turn. wheels The path of atires of the rear vehicle. The of a turning maximum truck angle does not coincide with that of the controls thefront tires, and thisturning minimum effect is shown in theof radius drawing. the vehicle. Swept path width The amount of roadway width that a truck cover in negotiating a turn and is equal to the amount of off tracking plus the width of the tractor unit. The most significant dimension affecting the swept path width of a tractor/ semitrailer is the distance from the kingpin to the rear trailer axle or axles. The greater this distance is, the greater the swept path width. TURNING CHARACTERISTICS TURNING CHARACTERISTICS TURNING CHARACTERISTICS MINIMUM TURNING RADII OF DESIGN VEHICLE MINIMUM TURNING RADII OF DESIGN VEHICLE DESIGN VEHICLE DIMENSION DESIGN VEHICLE DIMENSION MINIMUM MINIMUMTURNING TURNINGPATH PATHFOR FORPASSENGER PASSENGERCAR CAR MINIMUM MINIMUM TURNING TURNING PATH PATH FOR FOR CONVENTIONAL CONVENTIONAL SCHOOL SCHOOL BUS BUS  DESIGN VOLUME Design or Traffic Volume is defined as the number of vehicles that pass a point on a highway, or a given lane or direction of a highway, during a specified time interval. Design volume indicates the service for which the improvement is being made and directly affects the geometric features of design such as width, alignment, grades, etc. The number of vehicles using a road in a given time determines the number of traffic lanes required and indicates whether there is a need for auxiliary lanes for slow speed traffic and or whether speed change lanes are required at intersections. In estimating the design volume, the minimum life is commonly assumed to be 10 to 15 years for a flexible pavement, and 20 years for a rigid pavement. A period of 20 years is widely used as a basis for design, for which the usual traffic increase on a highway improvement is in the range of 50 to 150%. Where the highway is to be an expressway, traffic increase is likely to be higher, in the range of 80 to 200%. DESIGN VOLUME AADT – Annual Average Daily Traffic ADT – Average Daily Traffic DHV – Design Hourly Volume DDHV – Directional Design Hourly Volume DSFR – Design Service Flow Rate Annual Average Daily Traffic (AADT) Average Daily Traffic (ADT) Determined by dividing a count of the The volume that results from total yearly traffic volume by the dividing a traffic count obtained number of days in a year. during a given time period by the σ 𝑻𝒓𝒂𝒇𝒇𝒊𝒄 𝑽𝒐𝒍𝒖𝒎𝒆 𝒊𝒏 𝟏 𝒀𝒆𝒂𝒓 number of days in that time period. 𝑨𝑨𝑫𝑻 = σ 𝑫𝒂𝒚𝒔 𝒊𝒏 𝟏 𝒀𝒆𝒂𝒓 σ 𝑻𝒓𝒂𝒇𝒇𝒊𝒄 𝑽𝒐𝒍𝒖𝒎𝒆 𝑨𝑫𝑻 = σ 𝑫𝒂𝒚𝒔 𝒊𝒏 𝑻𝒊𝒎𝒆 𝑷𝒆𝒓𝒊𝒐𝒅 Future Future Average Average Daily Daily Traffic Traffic (ADT) (ADT) Adjusted ADT value considering an annual growth rate 𝑨𝑫𝑻𝑨𝒅𝒋𝒖𝒔𝒕𝒆𝒅 = 𝑨𝑫𝑻(𝟏 + 𝑮𝒓𝒐𝒘𝒕𝒉 𝑹𝒂𝒕𝒆)𝑵𝒐. 𝒐𝒇 𝒀𝒆𝒂𝒓𝒔 3% is a commonly assumed growth rate Design Hourly Volume (DHV) The DHV is a two-way traffic volume that is determined by multiplying the ADT by a percentage called the K-factor. 𝑫𝑯𝑽 = 𝑨𝑨𝑫𝑻 × 𝑲 K-factor is generally 12% to 18% for Rural and 8 to 12% for Urban. The DHV is usually the 30th highest hourly volume for the design year, commonly 20 years from the time of construction completion. Directional Directional Design Design Hourly Hourly Volume Volume (DDHV) (DDHV) The DDHV is the one-way volume in the predominant direction of travel in the design hour, expressed as a percentage of the two-way DHV. 𝑫𝑫𝑯𝑽 = 𝑫𝑯𝑽 × 𝑫 = 𝑨𝑨𝑫𝑻 × 𝑲 × 𝑫 D-factor normally varies from about 50 to 80% of two-way DHV, with an average of 67%. Design Service Flow Rate (DSFR) The DSFR is the amount of traffic in the peak 15-minute time period in one direction. 𝑫𝑫𝑯𝑽 𝑫𝑺𝑭𝑹 = 𝑷𝑯𝑭 𝑷𝒆𝒂𝒌 𝑯𝒐𝒖𝒓 𝑽𝒐𝒍𝒖𝒎𝒆 𝑷𝑯𝑭 = 𝟒×(𝑯𝒊𝒈𝒉𝒆𝒔𝒕 𝟏𝟓−𝑴𝒊𝒏𝒖𝒕𝒆 𝑽𝒐𝒍𝒖𝒎𝒆) DESIGN SPEED Speed is one of the most important factors considered by travelers in selecting alternative routes or transportation modes. The speed of vehicles on a road depends, in addition to capabilities of the drivers and their vehicles, upon five general conditions: a. the physical characteristics of the roadway b. the amount of roadside interference c. the weather d. the presence of other vehicles e. speed limitations (established either by law or by traffic control devices) DESIGN SPEED Design speed is a selected speed used to determine the various geometric design features of the roadway. It is the maximum safe speed that can be maintained over a specified section of the highway when conditions are so favorable that the design features of the highway govern. The selected design speed should be consistent with: a. the functional classification of the highway b. its surrounding land use c. topography d. driver’s anticipated operating speed OPERATING SPEED The speeds at which vehicles are observed operating during free-flow conditions. The 85th percentile of the distribution of observed speeds is the most frequently used measure of the operating speed associated with a particular location or geometric feature. DESIGN SPEED The objective in design of any engineered facility used by the public is to satisfy the public's demand for service in an economical manner with efficient traffic operations and with low crash frequency and severity. The facility should accommodate nearly all demands with reasonable adequacy and also should only fail under severe or extreme traffic demands. The Handbook of Highway Engineering (2006, Taylor & Francis) Freeways, expressways, and other rural highways = 110 kph Urban arterials = 30 to 70 kph MIN. RECOMMENDED DESIGN SPEED MIN. RECOMMENDED DESIGN SPEED  CROSS-SECTION DESIGN The cross section of a typical highway has latitude of variables to consider such as: The volume of traffic Character of traffic Speed of the traffic Characteristics of motor vehicles and of the driver CROSS-SECTION DESIGN A cross section design generally offers the expected level of service for safety and a recent study showed that: 1. A 7.20 meters wide pavement has 18% less accident compared with pavement narrower than 5.50 m wide. 2. A 7.20 meters wide pavement has 4% fewer accidents than the 6.00 meters wide roadway. 3. Accident records showed no difference between the 6.60 meters and the 7.20 meters wide pavement. 4. For the 6.00 m, 6.60 m, and 7.20 meters wide pavement with 2.70 to 3.00 m wide shoulder, recorded accident decreases by 30% compared to 0 to 0.60 m wide shoulder, and 20% compared with a 0.90 to 1.20 meters wide shoulder. RECOMMENDED PAVEMENT WIDTH PAVEMENT DIMENSIONS FOR DIVIDED HIGHWAYS PAVEMENT DIMENSIONS FOR DIVIDED HIGHWAYS PAVEMENT DIMENSIONS FOR DIVIDED HIGHWAYS PHYSICAL PHYSICAL ELEMENTS ELEMENTS HIGHWAY HIGHWAY CAPACITY CAPACITY ACCESS ACCESS CONTROL CONTROL AND AND MANAGEMENT MANAGEMENT PEDESTRIAN PEDESTRIAN FACILITIES FACILITIES BICYCLE BICYCLE FACILITIES FACILITIES SAFETY SAFETY ENVIRONMENT ENVIRONMENT HIGHWAY CAPACITY  BASIC CAPACITY The maximum volume of vehicles per hour that can pass a certain point or section of a road in a given time under the ideal condition. The maximum number of vehicles that can pass a given section during a given period of time under prevailing (most frequent/usual) roadway, POSSIBLE CAPACITY traffic and control condition. It is the maximum number of vehicles that can pass a given point on a lane or DESIGN CAPACITY roadway during one hour with creating unreasonable delay under the prevailing roadway and traffic conditions. https://www.aboutcivil.org/highway-capacity-definition-types-factors.html  Factors FactorsAffecting Affecting Highway HighwayCapacity Capacity https://www.aboutcivil.org/highway-capacity-definition-types-factors.html 1 LANE WIDTH A lane width is the cross- sectional dimension of a lane, perpendicular to the direction of travel, measured from the center of lane markings and the faces of curbs. Vehicular Travel Lane Vehicular travel lanes are lanes used by vehicles travelling along a route. 1 LANE WIDTH  2 WIDTH OF SHOULDER A highway shoulder is a portion of the road that falls outside the outer lane and is designed for emergency use by traffic. https://fixautousa.com/blog/danger-of-highway-shoulder/ 2 WIDTH OF SHOULDER  3 LATERAL CLEARANCE Lateral clearance is 1.8 m. A minimum of 3.6 m of total lateral clearance in the direction of travel. Clearances are measured from the edge of the outer travelled lanes (shoulders included) and lateral clearance of 1.8 m or greater are considered to be equal to 1.8 m. No direct access points along the highway. https://www.civil.iitb.ac.in/tvm/nptel/553_MlHway/web/web. html 4 COMMERCIAL VEHICLES 5 ROAD ALIGNMENT AND GEOMETRY (CURVES, SUPER ELEVATION ETC.) 6 EXISTENCE OF INTERSECTIONS  7 ONE WAY OR TWO-WAY TRAFFIC AND NUMBER OF LANES A two-way street is a street that allows vehicles to travel in both directions. Sometimes one portion of a street is a two-way and the other portion is one-way. If there is no line, a car must stay on the appropriate side and watch for cars coming in the opposite direction and prepare to pull over to let them pass. https://philosophy-question.com/library/lecture/read/148080-what-is- difference-between-one-way-and-two-way-road#0 8 DRIVERS AND VEHICULAR CHARACTERISTICS  HIGHWAY HIGHWAY CAPACITY CAPACITY It is the ability of a road to accommodate traffic volume. TRAFFIC VOLUME It is the number of vehicles passing a given point on a roadway during a specified time period. This is usually expressed as vehicles per hour. TRAFFIC TRAFFIC VOLUME VOLUME COUNT COUNT Is counting of the number of vehicles passing through a road over a period. It is defined as the procedure to determine mainly volume of traffic moving on the roads at a particular section during a particular time. It is usually expressed in terms of Passenger Car Unit (PCU). https://www.aboutcivil.org/highway-capacity-definition-types-factors.html Passenger Car Unit (PCU) is a metric used to assess traffic-flow rates on a highway. A Passenger Car Unit is a measure of the impact that a mode of transport has on traffic variables (such as headway, speed, density) compared to a single standard passenger car. This is also known as passenger car equivalent. For example, typical values of PCU are: Knowledge of highway capacity is essential to properly fit a planned highway to traffic demands. ACCESS ACCESS MANAGEMENT MANAGEMENT AND CONTROL AND CONTROL  ACCESS MANAGEMENT is the planned and regulated interaction between the roadway network and property access. https://www.codot.gov/business/designsupport/bulletins_manuals/cdot- roadway-design-guide-2018/dg18-ch11 PEDESTRIAN PEDESTRIAN FACILITIES FACILITIES https://cait.rutgers.edu/generating-power-every-time-you-hit-the-road/ BICYCLE FACILITIES SAFETY AND ENVIRONMENT ECONOMIC ECONOMIC FACTORS FACTORS Highway economics is concerned with the cost of a proposed improvement and the benefits resulting from it  HIGHWAY INTERSECTION AT GRADE  HIGHWAY INTERSECTION AT GRADE The intersection are generally found at locations where a major road and minor streets meet, two major roads intersect, etc. The intersections require a signal system, which is to be designed based on number of vehicles arriving at the intersection. At grade intersection implies that both the roads at intersection are at the same elevation. The movements possible at the intersection are through traffic one, weaving movement to the left, merging movement to the right, etc. The at grade intersection will require controlled movement maintaining the signalized intersections, when the higher volume of traffic passes through and are making left turn movements. At grade intersection will have conflicting traffic movements, increasing the chances of collision with one another. When the traffic volume becomes very high in the ‘At grade intersection’, the grade separated intersections are required. https://www.chegg.com/homework-help/definitions/at-grade-intersections-8 https://www.youtube.com/watch?v=XCV0Eeemt1g ELEMENTS OF ROADS AND HIGHWAYS (SECOND EDITION) BY MAX B. FAJARDO, JR. ELEMENTS OF ROADS AND HIGHWAYS (SECOND EDITION) BY MAX B. FAJARDO, JR. ELEMENTS OF ROADS AND HIGHWAYS (SECOND EDITION) BY MAX B. FAJARDO, JR. ELEMENTS OF ROADS AND HIGHWAYS (SECOND EDITION) BY MAX B. FAJARDO, JR. ELEMENTS OF ROADS AND HIGHWAYS (SECOND EDITION) BY MAX B. FAJARDO, JR. http://files.3-1-semester.webnode.com/200000066-d929eda289/C%207-Design%20of%20Intersections.pdf  TYPES OF AT GRADE INTERSECTIONS AT GRADE INTERSECTIONS MAY BE CLASSIFIED INTO TWO BROAD GROUPS: ◘UN CHANNELIZED INTERSECTIONS ◘CHANNELIZED INTERSECTIONS ◘SPECIAL TYPE – ROTARY INTERSECTION http://files.3-1-semester.webnode.com/200000066-d929eda289/C%207-Design%20of%20Intersections.pdf  UN CHANNELIZED INTERSECTION INTERSECTION AREA IS PAVED AND THERE IS ABSOLUTELY NO RESTRICTION TO VEHICLES TO USE ANY PART OF INTERSECTION AREA. HENCE THE UN CHANNELIZED (ALL – PAVED) INTERSECTIONS ARE THE LOWEST CLASS OF INTERSECTION EASIEST IN THE DESIGN BUT MOST COMPLEX IN TRAFFIC OPERATIONS RESULTING IN MAXIMUM CONFLICT AREA AND MORE NUMBER OF ACCIDENTS, UNLESS CONTROLLED BY TRAFFIC SIGNALS OR POLICE http://files.3-1-semester.webnode.com/200000066-d929eda289/C%207-Design%20of%20Intersections.pdf  UN CHANNELIZED INTERSECTION PLAIN INTERSECTION: PROVISION FOR ADDITIONAL PAVEMENT WIDTH FOR TURNING MOVEMENTS FLARED INTERSECTION: PROVISION FOR ADDITIONAL PAVEMENT WIDTH FOR TURNING MOVEMENTS http://files.3-1-semester.webnode.com/200000066-d929eda289/C%207-Design%20of%20Intersections.pdf http://files.3-1-semester.webnode.com/200000066-d929eda289/C%207-Design%20of%20Intersections.pdf  CHANNELIZED INTERSECTION CHANNELIZED INTERSECTION IS ACHIEVED BY INTRODUCTION OF ISLANDS INTO THE INTERSECTIONAL AREA, THUS REDUCING THE TOTAL CONFLICT AREA AVAILABLE IN THE UN CHANNELIZED INTERSECTION. THESE ISLANDS HELP TO CHANNELIZED TURNING TRAFFIC TO CONTROL THER SPEED AND ANGLE OF APPROACH AND TO DECREASE THE CONFLICT AREA AT THE INTERSECTION http://files.3-1-semester.webnode.com/200000066-d929eda289/C%207-Design%20of%20Intersections.pdf http://files.3-1-semester.webnode.com/200000066-d929eda289/C%207-Design%20of%20Intersections.pdf http://files.3-1-semester.webnode.com/200000066-d929eda289/C%207-Design%20of%20Intersections.pdf http://files.3-1-semester.webnode.com/200000066-d929eda289/C%207-Design%20of%20Intersections.pdf  ROTARY INTERSECTION Rotary intersections or roundabouts are special form of at-grade intersections laid out for the movement of traffic in one direction around a central traffic island. Essentially all the major conflicts at an intersection namely the collision between through and right-turn movements are converted into milder conflicts namely merging and diverging. The vehicles entering the rotary are gently forced to move in a clockwise direction in orderly fashion. They then weave out of the rotary to the desired direction. http://files.3-1-semester.webnode.com/200000066-d929eda289/C%207-Design%20of%20Intersections.pdf http://files.3-1-semester.webnode.com/200000066-d929eda289/C%207-Design%20of%20Intersections.pdf http://files.3-1-semester.webnode.com/200000066-d929eda289/C%207-Design%20of%20Intersections.pdf  ADVANTAGES OF ROTARY INTERSECTION Traffic flow is regulated to only one direction of movement, thus eliminating severe conflicts between crossing movements. All the vehicles entering the rotary are gently forced to reduce the speed and continue to move at slower speed. Thus, more of the vehicles need not to be stopped. Because of lower speed of negotiation and elimination of severe conflicts, accidents and their severity are much less in rotaries. Rotaries are self governing and do not need practically any control by police or traffic signals. They are ideally suited for moderate traffic, especially with irregular geometry, or intersections with more than three or four approaches. http://files.3-1-semester.webnode.com/200000066-d929eda289/C%207-Design%20of%20Intersections.pdf  DISADVANTAGES OF ROTARY INTERSECTION Even when there is relatively low traffic, the vehicles are forced to reduce their speed. All the vehicles are forced to slow down and negotiate the intersection. Therefore the cumulative delay will be much higher than channelized intersection. Rotaries require large area of relatively at land making them costly at urban areas. The vehicles do not usually stop at a rotary. They accelerate and exit the rotary at relatively high speed. Therefore, they are not suitable when there is high pedestrian movements http://files.3-1-semester.webnode.com/200000066-d929eda289/C%207-Design%20of%20Intersections.pdf  GUIDELINES FOR THE SELECTION OF ROTARIES There are few guidelines that help in deciding the suitability of a rotary: Rotaries are suitable when the traffic entering from all the four approaches are relatively equal. A total volume of about 3000 veh/hr can be considered as the upper limiting case and a volume of 500 veh/hr is the lower limit A rotary is very beneficial when the proportion of the right-turn traffic is very high; typically if it is more than 30 percent. Rotaries are suitable when there are more than four approaches or if there is no separate lanes available for right-turn traffic. Rotaries are ideally suited if the intersection geometry is complex http://files.3-1-semester.webnode.com/200000066-d929eda289/C%207-Design%20of%20Intersections.pdf http://files.3-1-semester.webnode.com/200000066-d929eda289/C%207-Design%20of%20Intersections.pdf ALTERNATIVE INTERSECT ION DESIGNS Restricted crossing U-turn (RCUT) https://www.sehinc.com/news/amazing-world-alternative-intersection-designs ALTERNATIVE INTERSECT ION DESIGNS MEDIAN U-TURN (MUT) https://www.sehinc.com/news/amazing-world-alternative-intersection-designs ALTERNATIVE INTERSECT ION DESIGNS DISPLACED LEFT-TURN INTERSECT ION (DLT) https://www.sehinc.com/news/amazing-world-alternative-intersection-designs ALTERNATIVE INTERSECT ION DESIGNS CONTINUOUS GREEN T-INTERSECT ION https://www.sehinc.com/news/amazing-world-alternative-intersection-designs HIGHWAY MEDIAN https://planningtank.com/transportation/traffic-island https://planningtank.com/transportation/traffic-island ELEMENTS OF ROADS AND HIGHWAYS (SECOND EDITION) BY MAX B. FAJARDO, JR. RIGHT OF WAY ELEMENTS OF ROADS AND HIGHWAYS (SECOND EDITION) BY MAX B. FAJARDO, JR. CLASSIFICATION OF HIGHWAY HIGHWAY a main road for travelling long distances, especially one connecting and going through cities and towns  EXPRESSWAY EXPRESSWAY Divided highway designed for high volumes of traffic An expressway is a divided highway with partial control on access TARLAC- PANGASINAN – LA UNION EXPRESSWAY Expressways can have speeds of 50 mph (up to 70 mph in some rural locations). NOTH LUZON EXPRESSWAY  FREEWAY It is a road designed for high speeds. A freeway has no at-grade intersections Design speeds vary from mph (sometimes 80 mph in flat rural areas In some urban areas, with populations under 50,000 the posted freeway speed is 65 mph. In more densely SUBIC-CLARK-TARLAC EXPRESSWAY populated urban areas (over 50,000), the posted speed is 55 or 60 mph, or in constrained areas, 50 mph. PATAPAT VIADUCT (PAGUDPUD, ILOCOS NORTE) ARTERIAL ROAD Lower speeds than highways and expressways Designed moderate-to-high capacity roads which can carry high volumes of traffic but at lower speeds than highways and MANILA NORTH ROAD expressways. Commercial areas are often located on PAN-PHILIPPINE HIGHWAY arterial roads. 3,379.73 km Luzon to Samar and Leyte to Mindanao  COLLECTOR COLLECTOR STREET STREET LOCAL LOCALROAD ROAD Low or moderate capacity road Low capacity Leads traffic to activity areas within a Low speed community Typically located in residential Intersects with arterial roads and local neighborhoods roads Local roads typically have a design A collector road is a low or moderate- speed of 20 – 40 mph. capacity road that leads traffic to activity areas within a community such as community centers, libraries, schools, etc. Collector roads typically have design speeds of 20 – 40 mph.  CUL-DE-SAC CUL-DE-SAC Dead end street with only one ingress/egress Created to limit through traffic These are typically created to limit through traffic. ACCIDENT ACCIDENT INFORMATION INFORMATION OBJECTIVES OF ACCIDENT STUDIES To study the causes of accidents and suggest corrective measures at potential location To evaluate existing design To compute the financial losses incurred To support the proposed design and provide economic justification to the improvement suggested by the traffic engineer To carry out before and after studies and to demonstrate the improvement in the problem. ACCIDENT ACCIDENTINFORMATION INFORMATION LOCATION LOCATION - Description and detail of location of accident DETAILS DETAILS OF OF VEHICLE VEHICLE INVOLVED INVOLVED - Registration number, description of vehicle, loading detail, vehicular defects NATURE NATURE OFOF ACCIDENT ACCIDENT - Details of collision, damages, injury and casualty ROAD ROAD AND AND TRAFFIC TRAFFIC CONDITION CONDITION - Details of road geometry, surface characteristics, type of traffic, traffic density etc.. PRIMARY CAUSES OF ACCIDENT - Details of various possible cases (already mentioned) which are the main causes of accident. COMMON COMMON WEALTH WEALTH AVENUE AVENUE KENNON KENNON ROAD ROAD HALSEMA HALSEMA HIGHWAY HIGHWAY HALSEMA HALSEMA HIGHWAY HIGHWAY LOCATION – Halsema Highway (Atok-Half Tunnel) DETAILS OF VEHICLE INVOLVED - a motorcycle, white van and a truck ROAD AND TRAFFIC CONDITION - lack of signage, the road has sharp curves PRIMARY CAUSES OF ACCIDENT - the motorcycle tried to overtake the truck without knowing that there is a white van behind him. https://www.youtube.com/watch?v=Oce2WuLF71I ACCIDENT AND CRASHES ACCIDENT An unforeseen and unplanned event or circumstances CRASHES A breaking to pieces by or as if by collision  SPEED DRIVER FATIGUE The speed of motor vehicles is at the core of Some of these factors with relevance to the road traffic injury problem. road traffic are long-distance driving ALCOHOL AND OTHER NONUSE OF MOTORCYCLE PSYCHOACTIVE SUBSTANCES HELMETS, SEAT-BELTS, AND CHILD the risk of a road traffic crash starts at low RESTRAINTS levels of blood alcohol concentration (BAC) and increases significantly when the driver's Factors Factors Correct helmet use can lead to a 42% reduction in the risk of fatal injuries and a BAC is ≥ 0.04 g/dl influencing Influencing 69% reduction in the risk of head injuries. crash Crash UNSAFE ROAD involvement involvement UNSAFE VEHICLES INFRASTRUCTURE Safe vehicles play a critical role in averting roads should be designed keeping in mind crashes and reducing the likelihood of serious the safety of all road users. injury DISTRACTED DRIVING INADEQUATE VISIBILITY Drivers using mobile phones are Seeing and being seen are fundamental approximately 4 times more likely to be prerequisites for the safety of all road users. involved in a crash than drivers not using a mobile phone. REFERENCES: The Handbook of Highway Engineering (2006, Taylor & Francis) https://www.webpages.uidaho.edu/niatt_labmanual/chapters/roadwaydesign/theoryandconcep ts/DesignControlsAndCriteria.htm http://onlinemanuals.txdot.gov/txdotmanuals/rdw/traffic_characteristics.htm http://www.mikeontraffic.com/85th-percentile-speed-explained/ https://www.youtube.com/watch?v=UpW7znocLxU&list=WL&index=89&t=178s https://www.youtube.com/watch?v=xr9P4be-P5Y&t=191s https://www.ite.org/technical-resources/topics/speed-management-for-safety/setting-speed- limits/ REFERENCES: https://www.dot.ny.gov/divisions/engineering/applications/traffic-data- viewer/tdv-definitions/Functional-Classifications.htm https://www.civil.iitb.ac.in/tvm/nptel/582_Accident/web/web.html http://www.dot.state.mn.us/roadway/data/docs/fc_summary_guidelines. pdf https://wazeopedia.waze.com/wiki/Philippines/Philippines/Speedlimit Speed Limit Law Philippines: Know It, Follow It: https://philkotse.com/safe- driving/speed-limit-law-philippines-know-it-follow-it-2485 https://www.youtube.com/watch?v=Oce2WuLF71I REFERENCES: https://www.who.int/news-room/fact-sheets/detail/road-traffic- injuries?fbclid=IwAR3TEzxABU-EYG4QwbSGIoyjZi6IxgpIsVgnlKcP- WxzAJdinwNM8IYCO2A https://www.who.int/violence_injury_prevention/road_traffic/activities/roads afety_training_manual_unit_2.pdf THANK YOU AND GOD BLESS!