INTRODUCTION OF TRANSPORTATION ENGINEERING a.

​ Measurable indicators
What is transportation engineering? -​ Queue length
-​ Deals with the planning, geometric design and traffic -​ Travel speed
operations on roads, streets and highways, their -​ Travel time
networks, terminals, abutting lands and relationships -​ Delay time
with other modes of transportation for the -​ Volume-Capacity Ratio (VCR)
achievement of safe, efficient and convenient -​ Signal Cycle Time (for signalized
movement of persons and goods. intersections)
-​ Applies engineering principles to help solve -​ Number of Traffic Accidents
transportation problems, and brings into play a b.​ Describable indicators
knowledge of psychology and habits of users of the -​ Presence of vehicle queue
transportation systems, aside from technical -​ Blocked or grid-locked intersections
foundations. -​ Presence of risky or dangerous maneuvers
Why is transportation engineering essential? -​ Chaotic pedestrian flows
-​ The greatest obstacles as an engineer faces in -​ Unsafe pedestrian crossings
applying sound principle of transportation engineering -​ Commuters spilling over on road pavement
is the fact the “everyone is a traffic expert”. -​ Uncontrolled roadside parking
-​ The unfortunate result of this attitude of expertise is -​ Frequent blowing of horns
the creation of traffic hazards when false theories of -​ Presence of makeshift control devices such
individuals or groups are put into effect. as signs, humps, barriers
-​ Without the training, the cure may be worse than the
disease. ROAD MAINTENANCE
How does the transportation engineer solve traffic problems? Road Maintenance
-​ As a trained professional, he/she looks at the -​ refers to the preservation of roads and bridge
symptoms, and in order to make a competent structures as nearly as possible to its original
diagnosis, she/he takes traffic counts, analyzes condition when first constructed or subsequently
accident statistics, studies speed data, examines improved.
roadway conditions, conducts research, and studies Why is maintenance necessary?
what other professionals are doing and the results -​ All pavements eventually require maintenance. The
that they achieved. chief reason being that stresses producing minor
-​ By providing roadway conditions that contribute to defects are constantly working in all pavements. Such
smooth and efficient traffic flow; stresses may be caused by change in temperature or
-​ Safety goes hand-in-hand with smooth traffic moisture content, by traffic or by small movements in
operations; the underlying or adjacent earth.
-​ Design a road to accommodate vehicles at a certain -​ Cracks, holes, depressions and other types of
speed and for a maximum capacity. distresses are the visible evidence of pavement wear.
Why not search a solution by trial and error? They are simply the end result of the process of wear
-​ It can be done. But trial and error can be expensive, which begins when construction ends. In urban areas,
in terms of lost man-hours and wasted fuel ditches dug through the pavement for water lines and
consumption. other utilities are a major area of pavement
-​ The motoring public will get confused with traffic maintenance.
pattern that changes every now and then. -​ Built roads without proper maintenance gradually
-​ More accidents could arise. deteriorate and become less serviceable to traffic,
Objectives of traffic management such that their conditions decline from good through
-​ Provision of even distribution or motor traffic activity fair till it becomes bad to the point of partial or total
through streets which fall into a similar functional disintegration, where they have to be rebuilt. During
category the decline of roads condition, the cost of transport
-​ Elimination of potentially hazardous locations rises as well.
-​ Improvement of traffic movement on the arterials
roads Types of maintenance work
-​ Improvement of drivers behavior ●​ Routine Maintenance - refers to maintenance activity
-​ Minimization of adverse effects to the operations of regularly performed throughout the year and includes
the arterials road system carriageway maintenance and roadside maintenance.
-​ Provision of adequate access to abutting properties ●​ Preventive Maintenance - refers to works more
on local streets. extensive than routine maintenance and helps
-​ Enhance the local environment prevent:
-​ Reduction of through traffic in residential street a.​ undue roadway deterioration
b.​ increased routine maintenance requirement
and
c.​ vehicular accidents.
●​ Long Term Performance Based Maintenance Contract
- The works in these consist of three components,
namely
a.​ Road and Bridge Performance Based
Maintenance,
b.​ Preventive Maintenance
c.​ Maintenance Backlog Reduction.
For routine maintenance activities
-​ Pothole patching, sealing of cracks on pavement
Traffic management schemes may be implemented:
-​ Grading and patching of shoulders
a.​ To improve road safety.
-​ Drainage cleaning and clearing
b.​ ….. Local amenity
-​ Roadside and feature maintenance: vegetation
c.​ ….. Local access and circulation
control, road sign and guardrail cleaning and
d.​ ….. The utility of arterial roads
repainting; and maintenance of other roadside
Rationale for traffic engineering and management
features.
-​ There are not enough roads to accommodate the
-​ Road markings maintenance
growing volume of motor vehicles.
-​ Bridge maintenance, cleaning of bridge decks,
-​ Greater reliance must therefore be placed on traffic
shelves framework and drainage, spot repainting and
management techniques to increase the practical
clearing of waterway flows.
capacity of available road space!
For periodic maintenance activities
What is a chokepoint?
-​ Large area resealing of pavement
-​ Can be an intersection, or section of a busy road, or a
-​ Re-graveling of shoulders.
block bounded by several roads
-​ Bridge parapet repairs, deck sealing, scour protection,
-​ Usually a segment of the busiest street where the
repainting
most number of vehicles pass each day.
Road Defects
What is a traffic bottleneck?
-​ Roadside Shoulder Defects
-​ A point in the traffic stream where the number of
●​ Eroded/No Shoulder
vehicles entering an upstream flow is greater than the
●​ Inverted Shoulder
number of vehicles that can get out at the
●​ Low Shoulder
downstream end.
●​ Lack of Gravel Material on Shoulder
 ●​ Soft Shoulder 4.​ It plays a vital role in development of rural areas of
●​ Water Ponding on Shoulder the country.
●​ Defective Shoulder (Steep Shoulder) 5.​ They improve the employment opportunities.
-​ Roadside Drainage and Other Shoulder Defects 6.​ Improves the contact between two countries.
●​ Clogged/Silted Line Canal 7.​ Improves the living standard of the country.
●​ Water Crossing Travelway 8.​ It helps to improve science and technology.
●​ Unpainted Headwall 9.​ It helps in industrial development throughout the
●​ Leaning Kilometer Post country.
●​ No Barricades, Warning Signs and Road 10.​ Enhances the import and export of the country.
Informative Sign Modes of Transportation in Civil Engineering
●​ Damaged Guardrail -​ There are three basic modes of transportation, these
●​ Thick Vegetation are land, water and air.
●​ Presence of Vegetation on Shoulder ROADWAYS & HIGHWAYS
❖​ Rutting - longitudinal depression that forms in the -​ Roadways are the means of transportation on land.
wheel path of a road under traffic loading Roadways are also known by highways. It consists
❖​ Pothole - holes of various shapes and sizes in the the modern highway as well as city streets, feeder
pavement surface roads and village roads, catering for a big range of
❖​ Base Failure - failure that affects the base with vehicles and the pedestrians. This is the only mode
settlement and depression along the road which is giving maximum service to one and all. It is
❖​ Corrugation - form of plastic movement typified by possible to provide door to door service only by road
ripples across the asphalt pavement transport.
❖​ Shoving - form of plastic movement resulting in RAILWAYS
localized bulging of the pavement surface -​ The steel tracks laid on the ground, over which the
❖​ Raveling - Loss or disintegration of stones, typically trains move is known as railways. Railways have
occurring in the wheel path been used for long as well as for short distances and
❖​ Bleeding - occurrence of excessive bitumen on the also for urban travels. For longer distances, railways
surface of the pavement transportation is more effective and advantageous
❖​ Edge Break - fretting along the edge of the pavement than highways.
-​ Large > 200mm AIRWAYS
-​ Moderate 75 - 200mm -​ In the airways, air crafts and helicopters are used. Air
❖​ Surface failure (DETERIORATION / DELAMINATION) system of transportation is one of the fastest system.
- loss of a discrete and large area of the wearing Air system of transportation provides comfort and also
coarse layer. save time to the passengers. But this system is more
❖​ Transverse Cracks - cracks running transversely costly compared to all other modes of transportation.
across the pavement WATERWAYS
❖​ Longitudinal Cracks - cracks running longitudinally -​ The transportation by water is the slowest among the
along the pavement four modes. This mode of transportation uses oceans,
❖​ Crocodile Cracks - cracks consisting of rivers, canals and lakes for the movement of boats
interconnected cracks forming small polygons and ships. By waterways human beings and materials
resembling a crocodile hide are used to transport from one place to another with
❖​ Shattered Slab - slabs that are severely cracked and the help of ships and boats etc. Transportation by this
need to be reblocked, slabs with 3 or more wide system is possible between the ports on the sea
cracks routes or along the rivers or canals where inland
❖​ Scaling - disintegration or loss of concrete from the transportation facilities are available.
surface of the pavement Transportation in the Philippines
❖​ Multiple cracks - combination of longitudinal and -​ It covers the transportation methods within this
transverse cracks within a block. archipelagic nation of over 7,500 islands. From a
❖​ Polishing - surface mortar and texturing worn away to previously underdeveloped state of transportation, the
expose coarse aggregate government has been improving transportation
❖​ Faulting at Transverse Joints - difference in levels of through various direct infrastructure projects, and
abutting concrete slabs these include an increase in air, sea, road, and rail
❖​ Spalling - chipping or breaking at joints transportation and transport hubs.
GOOD PRACTICES -​ Jeepneys are a popular and iconic public utility
-​ Application of thermoplastic pedestrian pavement vehicle. They have become a symbol of the Philippine
markings culture.Another popular mode of public transportation
-​ Provision os side ditching in the country is the motorized tricycles, especially
-​ Vegetation control along road shoulders common in smaller urban and rural areas.
-​ Reshaping of unpaved shoulder -​ The Philippines has four railway lines: Manila Light
-​ Seal coating of pavement with ravelling Rail Transit System Line 1, Manila Light Rail Transit
-​ Provision of bridge name, load limit sign and zebra System Line 2, Manila Metro Rail Transit System Line
painting 3, and the PNR Metro Commuter Line operated by
-​ Uncompacted and inverted road shoulder the Philippine National Railways. There are also
-​ Squaring was not undertaken before asphalt patching steam engines found in Visayas which operate sugar
-​ Low shoulders mills such as Central Azucarera. Taxis and buses are
-​ Non provision of centerline and edge line pavement also important modes of public transport in urban
markings areas.
-​ Non-removal of shrubs on bridge expansion joints -​ The Philippines has 12 international airports and has
-​ Non-removal of spoil materials more than 20 major and minor domestic airports
-​ Proper lane delineation serving the country. The Ninoy Aquino International
-​ Road Signs and Guardrails on Curves Airport is the main international gateway to the
-​ Provision of Adequate Shoulders Philippines.
-​ The busiest port is the Port of Manila, especially the
PHILIPPINE TRANSPORTATION SYSTEM Manila International Cargo Terminal and the Eva
Transportation Engineering Macapagal Port Terminal, both in the pier area of
-​ involves in the planning, design, operation, and Manila. Other cities with bustling ports and piers
maintenance of safe and efficient transportation include Bacolod, Batangas City, Cagayan de Oro,
systems. Cebu City, Davao City, Butuan, Iligan, Iloilo City, Jolo,
Role and Importance of Transportation Engineering Legazpi City, Lucena City, Puerto Princesa, San
-​ Transportation contributes to the economical, Fernando, Subic, Zamboanga City, Cotabato City,
industrial, social and cultural development of any General Santos City, Allen, Ormoc, Ozamiz, Surigao
country. Transportation is vital for the economic and Tagbilaran. Most of these terminals comprise the
development of any country. Every commodity needs Strong Republic Nautical Highway, a nautical system
transport facilities both at the production stage as well conceptualized under the term of President Gloria
as distribution stage. Macapagal Arroyo where land vehicles can use the
Importance of Transportation roll-on/roll-off (ro-ro) ferries to cross between the
1.​ They play an important role in the economic, social different islands.
and commercial development of the country.
2.​ They help in cultural development of the country.
3.​ They help in political development of the country.
TRAFFIC IMPACT ASSESSMENT
speed level, but significant increase in driver
vigilance is required at this level.
-​ Minimum average spacing between the vehicles is
in the range of 67 m.
-​ Queues may be expected to form behind any
significant blockage.

Level of Service D
-​ Represents the average speeds begin to decline
with increasing flows.
-​ Freedom to maneuver within the traffic stream is
Components of a Complete Feasibility Study on Roads noticeably restricted.
1.​ General profile of the study area -​ At this level, density deteriorates more quickly with
2.​ Economic analysis flow. The spacing between the vehicles is about 50
3.​ Environmental impact assessment m.
4.​ Development benefits quantification -​ As the traffic stream has little space to absorb
5.​ Right-of-way strip planning disruptions, minor incidents can lead to queuing of
6.​ Non-quantifiable benefits vehicles.
7.​ Traffic impact assessment
8.​ Design and cost estimation Level of service E
CAPACITY -​ Defines operation at capacity.
-​ Capacity analysis tries to give a clear understanding -​ At this level, the stream reaches it’s maximum
of how much traffic a given transportation facility can density limit.
accommodate. -​ There will be no usable gaps in the stream and
-​ The highway capacity depends on certain conditions: even slight disruptions will cause a breakdown,
1.​ Traffic conditions: It refers to the traffic with queues forming rapidly behind the disruption.
composition in the road such as the mix of -​ Maneuvering within the traffic stream becomes
cars, trucks, buses etc. in the stream. It also extremely difficult.
include peaking characteristics, proportions
of turning movements at intersections and Level of service F
the like. -​ Describes conditions in a queue that has formed
2.​ Road way characteristics: This points out to behind a point of breakdown or disruption.
the geometric characteristics of the road. -​ As vehicles shuffle through the queue, there may
These include lane width, shoulder width, be periods when they move quickly, and others
lane configuration, horizontal alignment and when they are stopped completely.
vertical alignment. -​ This level of service is used to describe the point of
3.​ Control conditions: This primarily applies to breakdown as well, even though operations
surface facilities and often refer to the downstream of such a breakdown may appear
signals at intersections etc. good.
Capacity is the maximum flow rate that a facility can -​ It represents the region of forced flow, having low
afford. This maximum flow rate is taken for the worst 15 speed, and complete breakdown of the system.
minutes of the peak hours while finding out the capacity.
LEVEL OF SERVICE CAPACITY VS. LEVEL OF SERVICE
-​ Level of service tries to answer how good is the -​ Capacity analysis gives a quantitative measure of a
present traffic situation on a given facility. facility while Level of Service gives a qualitative
-​ Level of service is defined based on the measure of measure of traffic.
effectiveness or (MOE). Typically three parameters Level of Service (LOS)
are used: speed and travel time, density, and delay. -​ LOS divides the quality of traffic into six levels ranging
-​ One of the important measures of service quality is form level A to level F. Level A represents the best
the amount of time spent in travel. Therefore, speed quality of traffic where the driver has the freedom to
and travel time are considered to be more effective in drive with free flow speed and level F represents the
defining LOS of a facility. worst quality of traffic.
-​ Density gives the proximity of other vehicles in the
Level of Service VCR Traffic Condition
stream. Since it affects the ability of drivers to
maneuver in the traffic stream, it is also used to
describe LOS. A < 0.20 Free flowing traffic
-​ Delay is a term that describes excess or unexpected
time spent in travel. B 0.21 - 0.50 Relatively free
Six levels of service flowing traffic

Level of Service A C 0.51 - 0.70 Moderate traffic

-​ Represents the zone of free flow.
-​ The traffic volume will be less, traffic will be D 0.71 - 0.85 Moderate / Heavy
experiencing free flow also. traffic
-​ The drivers will be having the complete freedom to
choose their desired speed.
E 0.86 - 1.00 Heavy traffic
-​ Even at maximum density, for this LOS the average
spacing between vehicles is 167 m.
F > 1.00 Saturation traffic
-​ Lane changes within the traffic stream, as well as
volumes,
merging and diverging movements, are made
stop-and-go
relatively easy.
situations
-​ The effect of minor incidents and point breakdowns
are easily aborted at this level. Types of Signals
1.​ Pre-time / Fixed Time
Level of Service B a.​ Single Program Controller
-​ Represents zone of reasonably free flow. b.​ Multiprogramming Controller
-​ Free flow speeds are still maintained at this level of 2.​ Time actuated
service. a.​ Semi - actuated
-​ The drivers freedom to choose their desired speed b.​ Fully - actuated
is only slightly restricted
-​ The lowest average spacing between vehicles is
about 100 m.
-​ The effects of small incidents and point
breakdowns are still easily contained.

Level of Service C
-​ The presence of other vehicles begins to restrict
the maneuverability within the traffic stream.
-​ Average speeds remain at or near the free flow
Phasing on the circulatory roadway are typically less
-​ (SIGNALIZED INTERSECTIONS) than 50 km/h
❖​ Splitter islands on each leg of the
roundabout
➢​ Roundabouts can be classified into three basic
categories according to size and number of lanes to
facilitate discussion of specific performance and
design issues:
●​ Mini-roundabouts

Weaving capacity at Roundabout

●​ Advantages
-​ Increase traffic safety ●​ Single-lane roundabouts
-​ Decrease vehicle delays
-​ Less expensive
-​ Deliver environmental benefits
●​ Disadvantages
-​ Unbalanced traffic flow
-​ Higher right-of-way space needed
-​ Difficult pedestrian crossing
-​ Vehicle progression disruption
Traffic Operations in Roundabouts
-​ Weaving - one movement must cross the path of
another along a length of facility without the aid of
signals or another traffic control devices. ●​ Multilane roundabouts

Weaving movements cross each other’s path

Merging movements join to form a single traffic stream.

Intersection is the most critical element of a road network .

➢​ Road crash between road-users
➢​ Long queue leads to traffic congestion
➢​ Air pollution
➢​ Unnecessary excessive fuel consumption
➢​ Delay of services
➢​ Characteristics of intersections
An intersection includes the areas needed for all
Diverging movements divided to form separate traffic
modes of travel: pedestrian, bicycle, passenger vehicle, truck,
streams
and transit. The intersection design addresses not only the
roadway pavement, but the adjacent sidewalks and pedestrian
ramps. Intersections are a key feature of roadway design in
four respects:
-​ Focus of activity
-​ Conflicting movements
-​ Traffic control
-​ Capacity
Intersection Functional Area
Design speed
-​ 30 kph for urban areas
-​ 40 kph for rural areas

A roundabout is an intersection with a central island

around which traffic must travel counterclockwise and in which
entering traffic must yield to circulating traffic.
! Not all circular intersections can be classified as roundabouts.
-​ Rotaries - are characterized by large diameter (often The functional area on the approach to an intersection
in excess of 100 m [300 ft]) and travel speeds within or driveway consists of three basic elements:
the circulatory roadway that exceed 50 km/h [30 (1) perception-reaction decision distance,
mph]. (2) maneuver distance, and
-​ Signalized traffic circles - are old-style circular (3) queue-storage distance
intersections in which traffic signals are used to Multi-leg intersection
control one or more entry-circulating points -​ Multileg intersections—those with five or more
-​ Neighborhood traffic circles - are typically built at the intersection legs—should be avoided wherever
intersections of local streets for traffic calming and/or practical.
aesthetics. -​ At locations where multileg intersections are used, it
-​ Modern roundabout - Modern roundabouts are may be satisfactory to have all intersection legs
circular intersections with specific design intersect at a common paved area, where volumes
and traffic control features that include: are light and stop control is used.
❖​ Yield control for all entering traffic
❖​ Channelized approaches
❖​ Appropriate curvature designed into the
intersection geometry so that travel speeds
 The simplest application of this principle on an -​ Refuge—to provide refuge for pedestrians. Most
intersection with five approach legs is to realign the diagonal islands combine two or all of these functions.
leg to join an adjacent leg at General types and shapes of islands and medians
sufficient distance from the
main intersection to form two
distinct intersections, each of
which can be operated simply,
as shown.

For an intersection with six

approach legs, two legs can be
realigned in adjacent quadrants
to form a simple four-leg
intersection at an appropriate
distance from the main intersection, which is itself converted to
a simple four-leg intersection as illustrated. Painted islands may be used at the traveled way edge. At
Intersection Conflict Points some intersections, both curbed and painted islands may be
desirable. All pavement markings should be reflectorized. The
use of thermoplastic striping, raised dots, spaced and raised
retroreflective markers, and other forms of long-life markings
also may be desirable.
Evaluation of Intersection Control Measures
-​ Uncontrolled Intersections
-​ Two-way Stop Control
-​ Signalization
-​ Rotary
-​ Underpass
Evaluation Factors
➢​ Functionality
●​ Time Delay Due to Intersection
●​ Level of Service
●​ Volume Diverted
●​ Accessibility to Connecting Roads
●​ Lane Operations
●​ Geometric Characteristics
How many conflict points are there in a typical modern ➢​ Construction
roundabout? ●​ Construction Period
Diverging - 4 ●​ Construction Method/difficulty
Merging - 4 ●​ Traffic Impact During Construction
Crossing - 0 ➢​ Social and environmental
●​ ROW Acquisition
●​ Accessibility
●​ Location of Bus Stop
●​ Drainage Improvement
●​ Aesthetics
➢​ Economic
●​ Excess Traffic Cost: Intersection
●​ Economic Indicator
●​ Sensitivity to Cost Variations
●​ Civil Works Cost and Supervision
●​ ROW Cost
Channelization
-​ It is the separation or regulation of conflicting traffic
movements into definite paths of travel by traffic
islands or pavement marking to facilitate the orderly
movements of both vehicles and pedestrians.
-​ Channelizing islands that control and direct traffic
movements into the proper paths for their intended
use are an important part of intersection design.
-​ Channelizing islands may be of many shapes and
sizes, depending on the conditions and dimensions of
the intersection.
-​ A common form is the corner triangular shape that
separates right-turning traffic from through traffic.
-​ Central islands may serve as a guide around which
turning vehicles operate.
Channeling islands
-​ Channelizing islands generally are included in
intersection design for one or more of the following
purposes:
➢​ Separation of conflicts
➢​ Control of angle of conflict
➢​ Reduction in excessive pavement areas
➢​ Regulation of traffic and indication of proper
use of intersection
➢​ Arrangements to favour a predominant
turning movement
➢​ Protection of pedestrians
➢​ Protection and storage of turning and
crossing vehicles
➢​ Location of traffic control devices
Islands serve three primary functions:
-​ Channelization—to control and direct traffic
movement, usually turning;
-​ Division—to divide opposing or same direction traffic
streams, usually through movements; and