highway engineering lecturer notes - Chapter 1&2

1 2

HIGHWAY ENGINEERING ECG 304

3 4

Intan Shafika Saiful Bahri Faculty of Civil Engineering UiTMPP

5 6

Course Outcomes 1. 2.

3.

4. 5.

Describe the process involved in the development and construction of highways Carry out simple traffic studies and apply the knowledge in highway geometric design and traffic control devices by using recommended standards and specification Perform simple flexible pavement design according to JKR Arahan Teknik (Jalan) method and the selection of appropriate material for used in the construction. Supervise road construction, identify road defect and recommends appropriate solution. Perform the standard highway laboratory tests and data analysis.

Programme Outcomes 1.

2. 3. 4. 5. 6.

7.

Ability to acquire & apply basic knowledge of science, mathematics & engineering. Ability to communicate effectively, not only with engineers but also with the public. Ability to identify, formulate & solve engineering problems. Ability to function on multi-disciplinary teams. Ability to act effectively as an individual and in a group, with leadership, managerial & entrepreneurial capabilities Understanding the social, cultural, global & environmental responsibilities & ethics of an engineering personnel & the need for sustainable development Recognizing the need to undertake lifelong learning & possessing the capacity to do so.

Course Description • Historical development of highways in Malaysia • Traffic Engineering theory • Road geometric design • Traffic control devices • Pavement design • Road construction and maintenance

Chapter 1 Content: 1. Development of highway transportation 2. Highway classification and administration 3. Feasibility studies and route location 4. Road safety and current issues

Learning Outcomes At the end of this chapter, students should be able to: •

• • •

Describe the process involved in the development and construction of roads and highway as general as well as in Malaysia. Describe the general aspects of highway classification and administration Explain the importance of feasibility studies and identify the route location consideration factors. Discuss on way to improve road safety and current issues (transportation challenges).

Development of highway transportation • Transportation : Everything involved in moving either the person or goods from the origin to the destination. Mobility Movements – different modes e.g walking, driving etc

Transportation Accessibility Entry and exit

Development of highway transportation (con’t)

Why do we provide and develop road infrastructure?

•

To expedite economy recovery development

•

May benefit the surrounding areas upgraded to reduce accidents, congestions

•

Investment in mode and road infrastructure – to meet the demands and private transportation

Development of highway transportation (con’t)

History of road construction

• Roman Roads • Metcalf’s Road (1717) • Telford’s Road (1757) • Mac Adam’s Road (1756)

Development of highway transportation (con’t)

Roman Roads Paving Stones Fine Concrete

Broken Stones

Rubble Stones

• Used by horses,

chariot, wagon – pulled by animals

• Made-up from

the stone blocks placed closed together

Development of highway transportation (con’t)

Metcalf’s Road • Insisted on good Gravel

Excavated Road Material

Large Stone Foundation

•

•

drainage and foundation or subbase carriageway was arched – assist surface water drainage Crossing soft ground, he introduced a subbase raft of bundled heather

Development of highway transportation (con’t)

Telford’s Road • Improved ride ability Gravel

Broken Stone

Hand Pitched Stone

•

- ‘sandwich’ smaller stones between the boulders smaller stones filled voids between the stone blocks – compacted until smooth surface obtained

Development of highway transportation (con’t)

Mac Adam’s Road Camber

Gravel

• Several layers of compacted stones • Foundation improvement – removing the topsoil

• Last decade before

independent – tar road constructed in cities and town – Mac Adam

• Animal drawn carts to mechanical and motorized vehicles

Development of highway transportation (con’t)

Pre-Independent Era

• Before independent – walking or animal’s

cart and few motorized car by means of footpath and bullock cart tracks • Rubber plantation and tin mining increase demand for a better serviceability of road network – weak laterite • Planning of road in Malaya – British Administration

Development of highway transportation (con’t)

Post-Independent Era

• Now, Malaysia has one of the finest systems

of road network system in the world • Bituminous or concrete road – provide accessibility to residents (urban or rural) • Expressway stretching from the north to the south of peninsular Malaysia (PLUS) • Federal highway – links between states

Post-Independent Era

Highway/Road Classification

• Roads are divided into two groups by area: Rural

* Located outside of cities * Serve as links between population centers

Urban

* Used for commuting & shopping trips * Serve areas of high density land

Rural Road • Expressway - divided highway for through traffic - full access control and grade separation at all intersection. - speed limit is 110 km/h • Highway - link up directly/indirectly federal capitals, state capitals. - serve long to intermediate trip lengths - speed high to medium (not important as expressway) - smooth traffic with partial access control

Rural road (con’t)

• Primary road - major roads within a state - serve intermediate trip lengths & medium travelling speed - smooth traffic with partial access control - link up state capitals, district capitals and major towns • Secondary road - major road within district - serve intermediate trip lengths with partial access control • Minor road - apply to all road other than mentioned earlier - serve mainly local traffic, short trip lengths, no access control

Urban Road • Expressway - as mentioned in rural road • Arterial - continuous road with partial access for through traffic within urban area - Convey traffic from residential area to CBD - smooth traffic flows and carry large traffic volume

Rural road (con’t)

• Collector - Serve as collector or distributor between the arterial and local road system - partial access control - penetrate and serve identifiable neighbourhoods, commercial areas and industrial areas • Local street - basic road networks within a neighbourhoods - serve direct access to abutting land - links to the collector road & short trip lengths - through traffic should be discouraged

Highway Administration Federal

• Under Federal Road Ordinance • Linking State Capitals, airport, railway station and ports

• Road within the FELDA land

scheme those with other regional land scheme constructed with Federal funds

Private

State

• Constructed with state funds

Local Authority

• City Hall, Municipal or Local Council

• Kampung (District Office) Roads – depend on jurisdiction

Traffic census Environmental Impact Assessment

Capacity

Class of Road

Route Location

Feasibility Study

Structures

Finalizing the Route

Route location Consideration Factors:

     

Topography – terrain Soil condition Environment Economy/socioeconomic Politic History

Route location (con’t)

2- Flat area rather than mountainous

1- Avoid crossing waterways

Example:

3- Avoid destruction/removal man-made culture 4- Avoid deep cuttings and expensive tunnel 5- Locate near to sources of pavement material

6- Avoid sudden changes in sight distance, especially near junction 7- Keep grades and curvature to minimum

8- Avoid ground of mining subsidence 9- Locate highway on soil that need least pavement thickness above it

10- River crossing should be right angle

Road Safety in Malaysia Multimedia Road Safety Campaign

Increase awareness and understanding of road safety How to improve? Proposed Amendments To Road Safety Act 1987

Improve heavier penalties on drivers – including mandatory jail

Ops STATIK and Ops SIKAP

Driver’s offences recorded and summonses were given Intro to Defensive Driving

Upgrading quality of instruction, instructors and training facilities at driving school

Road Safety in Malaysia (con’t)

Safety helmet & safety clothing

Safety campaigns at state & district level

How to improve?

Proposal for Dedicated Motorcycle Lane

Be a policy decision for proposed new highway

Proposal to Limit Max Speeds of Motorcyclists

To reduce accidents and fatalities

Still under study by The Ministry of Transport

Standard application to Malaysian Roads Higher design speeds for roads those provide long distance travel Lower design speeds for roads those serve local traffic, where the effect of speed is less significant Higher standard for roads with heavier traffic

In Malaysia, design standards for roads are classified into 7 groups for urban & rural categories. The reason why road design standards in Malaysia need to be standardized particularly with their geometric design features are as follows: To provide a uniformity in the design of roads based on the performance requirements To provide consistent, safe and reliable road facilities for traffic movement To provide a guide for less subjective decisions on road design

Agencies Involved In Highway & Traffic

• JKR (The Public Works Department) Implementation of development projects (federal road, state road, bridge & airport) make sure all roads are in a good condition & safety • JPJ (The Road Transport Department) increase road safety through observation of motorized vehicles & drivers implement the Road Transport Act 1987 Update the road tax system • LLM (Malaysia Highway Authority) plan, design, construct & maintain highway links & facilities. collect the toll & other payment which are related.

Benefits of Highway Privatization

• • •

• •

Reduce government financial burden Cost saving due innovation in const. techniques Users enjoy – improved standard of service & greater accessibility Earlier implementation and completion of highway project Create more job opportunity

Roadway Ideal Conditions Lane width 3.6 m Clearance 1.8 m Free-flow speed of 100 km/h No No Passing Zone on two-lane highway No parking near the curb Level terrain No pedestrians Only passenger cars in the traffic stream (no heavy vehicles)

Transportation System Challenges • Transportation system exists to meet perceived social and economic needs. • As the transportation system itself evolves, situations arise as a problem – serve as challenges to the transportation engineering profession. • These challenges are 1. Managing congestion – by demand or supply measures 2. Improving safety – traffic accidents concern 3. Providing equal access – poor, elderly, and physically handicapped 4. Protecting the environment – EIA 5. Incorporating new technology - ITS 6. Securing financial resources - funding

Current Issue • Serious urban traffic congestion • Highway-related crashes - Over 40,000 traffic fatalities each year • Delay • Parking difficulties • Pollution – noise and air (CO,NO, hydrocarbons)

Chapter 2 Content: 1. Spot speed studies, design speed, operating speed, running speed and speed limit 2. Traffic volume characteristics, flow rate, highway capacity and Level of service (LOS)

Learning Outcomes At the end of the chapter, students should be able to: 1. Carry out simple speed studies and apply the knowledge in highway geometric design by using recommended standards and specification. 2. Carry out simple volume studies and apply the knowledge in traffic signal design by using recommended standards and specification.

Contents • Traffic Stream Parameters  Microscopic  Macroscopic • Measurements  Manual  Inductive loops  Speed guns • Traffic Stream Models  Green shield's speed-density relationship  Fundamental diagram

Traffic Studies • Three (3) main categories:1. Inventories A list or graphic display of existing information – street widths, parking spaces, transit routes, etc 2. Administrative Existing engineering records, available in government agencies & departments 3. Dynamic collection of data under operational conditions – speed, traffic volume, travel time & delay, parking and crashes.

Plan, improve road system

Distribution & performance of existing traffic

Traffic measurements

Traffic flow & speed

Traffic planning studies

Implemented with the help of 3-E’s (Engineering, Enforcement and Education)

Microscopic vs. Macroscopic Measures

• 1. 2. 3. • 1. 2. 3.

Microscopic measures: individual vehicle Time headway: hi (sec/veh) Space headway: si (ft/veh or km/veh) Speed of individual vehicle: ui (mi/hr or km/hr) Macroscopic measures: average of n vehicles Flow: q (veh/hr or vph) Density: k (veh/mi or veh/km) q = uk Speed: u (mi/hr or km/hr)

Spot Speed Studies  Study of speed of traffic at one point or spot on a traffic way  Aims – to determine the enforceable speed limits  To estimate the speed distribution of the traffic stream

60 110 km/j

90 km/j

km/j

80 km/j

30 km/j

Time of day & Duration 1. Establish posted speed limits 2. Observe speed trends 3. Collect basic data

Traffic is free-flowing, usually offpeak hours

4. Response to citizen complaints → reflects the nature of complaints Duration at least 1 hour and the sample size is at least 30 vehicles.

Where to make spot speed studies? Free flow Junction High frequency of accident rate Important locations for traffic operation Representative location for basic data survey

Factors affecting spot speed studies

OR

OR

Driver Vehicle Roadway Traffic Environment

OR

Application of spot speed data

For trends in the operating speed

For speed at problem location

110 km/j

For research studies

For traffic operation – speed limit & safe speed at curve

For geometric design features

Methods of Measurement Speed Studies

Automatically

Manually

- Road detectors - Radar speed meter 200m

(commonly used) Or Sonic detector

0 sec 8 sec

Speed = distance/time = 200m/8sec V = 25m/s = 90kph

- Time laps camera

Manual  Observe the time required by a vehicle to cover short distance.  Direct timing procedure  Two reference points are located at a roadway, fixed distance apart.  Observer starts and stops a stopwatch as a vehicle enters & leaves the test section.  It is most uncomplicated way.  Disadvantages: Parallax effect

Road detectors  Classified into two general categories:

a) Pneumatic road tubes  two tubes laid across the lane  an impulse is recorded when the front



wheels pass over the first tube, second impulse is recorded when the front wheels pass over the second tube. time elapsed between the two impulses & distance between the tubes are used to compute the speed.

b) An inductive loop  rectangular wire loop buried under the roadway surface.

 Advantages:

a) human errors are reduced b) accurate results  Disadvantages:

a) devices rather expensive b) affect driver behavior c) wear & tear

Speed Meter  Two types:

a) Radar speed meter  transmit signal onto a moving vehicle  change in frequency between transmitted signal & reflected signal = speed.  operating distance about 45 m

b) Sonic detector meter  using ultrasonic tone (18-20 kHz)  output in current voltage that is proportional to vehicle speed.

 Advantages:

a) portable b) reduced the influence on driver behaviour.  Disadvantages:

a) difficult for two-lane road b) expensive

Electronic-principle detectors  Vehicles is detected through electronic means.  Traffic characteristics can be obtained – speed, volume, queues & headways.  Consists of an electronic camera & microprocessor.  Advantages: permanent visual will be recorded

Definition:  Speed – Rate of movement of the vehicle, expressed in miles/hour (mi/h) or kilometers/hour (km/h).  Average spot speed /Arithmetic mean speed / Time mean speed (*) - Arithmetic mean of all observed vehicle speeds. Total of spot speeds/No of vehicles.  Overall travel time - Time travel including stop and delays.  Overall travel speed/journey speed (*) - The speed over a specified section of highway. Distance/overall travel time.

 Operating speed (*) the highest overall speed a driver can travel under a favorable weather condition w/out exceeds the speed limits  Running speed (*) the average speed maintained over a particular distance which the vehicle is in motion. Distance/ (Time travel – time delay)  Running delay delay caused by interference between components of traffic (stream flow, parking)  Design speed the speed determined for design as related to the physical features of a highway that might influence vehicle operation. the max safe speed that can be maintained over a specified section of highway when conditions are so favorable.

 Median speed speed at the middle value in a series of spot speeds that are arranged in ascending order  Modal speed speed value with highest frequency (observation) in a sample of spot speeds.  Pace/Mode the range of speed (5-10 km/h intervals) that has the greatest number of observations.  Standard deviation of speeds measure of the spread of the individual speeds.  Space mean speed the arithmetic mean of speeds of vehicles occupying a relatively long section of street or highway at given instant.

Analysis and data presentation (refer Ex 4.2 pg 93)

• Table Speed group 10 – 14.9

Mean speed, v

Frequency, f

12.5

0

frequency

• Histogram

Speed, kph

fv

%f

Cumulative % f

f(v-u)2

0

0

• Frequency distribution • Cumulative distribution

Time mean speed vs. space mean speed Six vehicles traveling through a section of a rural secondary road with the speeds measured at 68, 71, 79, 82, 76 and 74 km/h respectively. Assuming every vehicle was traveling at constant speed over the section of road, calculate the space mean speed and time mean speed.

Time mean speed = Total speed No of vehicles

Space mean speed = Total distance Total time

Volume Studies • collect data on the no of vehicles and/or pedestrians that pass a point on a highway facility during a specified time period.

• Time period – little as 15 min to as much as a year, depends on the use of the data.

• Data collected – put into subclasses.

Types of Traffic Daily Volume  Average Annual Daily Traffic (AADT) Average 24 hour volume over a year

 Average Annual Weekday Traffic (AAWT) Average 24 hr volume occurring on weekdays over a year

 Average Daily Traffic (ADT) Same as AADT, but average over period less than a year, say, a month

 Average Weekday Traffic (AWT) Same as AAWT, but average over period less than a year, say, a month

Applications of AADT/ADT

• 1. 2. 3. 4. 5. • 1. 2.

AADT Applications Estimation of highway use Estimation of trends Economic feasibility evaluation Planning Maintenance ADT Applications Planning of highway activities Measurement of current demand

Peak Hour Volume (PHV) • The max no of veh passing a point on a highway over 60 consecutive minutes • Peak Hour Factor (PHF) PHF = Peak hour volume 4 x The maximum15 minute volume • Mainly used for urban: 1. Highway design (e.g. highway classification, no of lanes, signalization) 2. Traffic management (e.g. capacity analysis, parking)

Example: PHF  Determine

(a) the hourly volume, (b) the peak rate of flow within the hour, and (c) the peak hour factor Time Period 8:00 – 8:15 AM

Volume 150

8:15 – 8:30 AM 8:30 – 8:45 AM 8:45 – 9:00 AM

155 165 160

Volume Characteristics  Three basis of traffic flow:

1. Hourly The traffic flow mostly for a day – traffic volume varies from hour to hour. 2. Daily Distribution of traffic flow every day from Sunday to Saturday in a week. 3. Monthly Distribution of traffic flow for each month from January to December in a year Refer figure 4.14 pg 110 in your textbook

Traffic Count The duration can be 1 hour, 1 day or 1 year Unit: no. of vehicle or passenger car unit (PCU) Traffic can be divided into type & class of vehicle – car, motorcycle, bus, lorry, etc PCU – standard unit of measurement designed to give the effect of an equivalent numbers of passenger cars.

Table 2.1: Conversion factor from no of veh to PCU

Equivalent Value in PCU’s

Vehicle Classification Passenger Cars Pedal Cycle Motor Cycles Light Vans Medium Lorries Heavy Lorries Buses

Rural Roads

Urban Roads

Roundabout

Traffic Signal/ Junction

1.00 0.50 1.00 2.00 2.50 3.00 3.00

1.00 0.33 0.75 2.00 2.50 3.00 3.00

1.00 0.20 0.75 2.00 2.80 2.80 2.80

1.00 0.20 0.33 2.00 1.75 2.25 2.25

Arahan Teknik (Jalan) 8/86, JKR

Methods of Conducting Volume Counts Manual method

• Involves one or more persons recording

• •

observed vehicles using a counter. Advantages: a) not required specialized b) accurate results Disadvantages: a) labour intensive – can be expensive b) cannot be use for long periods of counting

Automatic Method

• Laying of surface detectors (pneumatic road tubes) or subsurface detectors (magnetic or electric contact devices) on the road. • Detect the passing vehicle & transmit the information to a recorder. • Advantages; a) not required specialized b) accurate results • Disadvantages; a) wear & tear b) disrupts traffic during installation

Types of Volume Counts • Cordon Counts * * * * *

conduct at central business district (CBD). imaginary closed loop as cordon area. intersection crossing the cordon line – count station. Volume counts of vehicles enter & leaving cordon area are taken. data used: planning parking facilities, updating & evaluating traffic operational technique.

• Screen Line Counts *

•

study area are divided into large sections by running imaginary lines (screen lines) across it. * traffic counts are taken at each point where a road crosses the screen line. Intersection Counts * determine vehicle classifications through movements & turning movements at intersections. * determine phase lengths & cycle time for signalized intersection, design of channelization.

Analysis of Traffic Volume Data

Flow (pcu/h/l)

Weekday Weekend

7.00

8.00

9.00

10.00 11.00 12.00 1.00

2.00

3.00

4.00 5.00 6.00 7.00

Time (a.m-p.m)

Hourly Volume Characteristics

Vehicle per day

Zone A Zone B

Sunday

Monday

Tuesday

Wednesday

Thursday

Friday

Saturday

Day per week

Daily Volume Characteristics

Flow (pcu/h/l)

- Increment of traffic volume

1998

1999

2000

2001

2002

2003

2004

2005

Year

Annually Volume Characteristics

Definition  Design Volume The volume of traffic estimated to use the road during the design life.  Design Vehicle A selected motor vehicle which the weight, dimensions & operating characteristics are used to establish highway design controls to accommodate vehicles of a designated type.

 Service volume Max volume of traffic that a designed roadway would be able to serve without undue congestion falling below prescribed level of service (LOS) at the time the traffic is at design hourly volume.

 Highway capacity Ability to accommodate traffic & usually expressed as no of vehicles that can pass a given point in a certain period of time at a given speed.  Level of service (LOS) Term used to classify the varying conditions of traffic flow that take place on highway. The various level of service range from the highest level (flow where drivers are able to travel at their desired speed with freedom to manoeuvre) to the lowest level (obtained during congested stop-start conditions).

Level of service (LOS)  The LOS of existing highway may be evaluated by comparing measured traffic volume to the capacity of that facilities.  Each road has its own capacity depending on a) speed b) travel time c) safety d) traffic interruption  LOS = volume/capacity

Free Flow Stable Flow

A B

Approaching Unstable Flow

Speed

C D E

Unstable Flow

F Forced Flow

Flow

Relationship of LOS to operating speed and Flow