MODULE 3: TRAFFIC CHARACTERISTICS

VEHICULAR SPEED

Can be measured instantaneously or averaged over distance or time

SPOT SPEED

Instantaneous speed of a vehicle at any specified point

GENERAL LOCATION

Trend stations are usually established along highways or mid-block road sections away from the influence of stop signs, traffic signals.

SPECIFIC LOCATION

Observers should be located in such a way that data are recorded without being noticed by the driver. Accumulation of onlookers should be avoided

TIME OF STUDY

The study be made for one hour or not less than 50 vehicles (preferably 100 for 50kph highway design speed)

9:00 AM-12:00 NN/3:00-6:00 PM/8:00-10:00 PM

When are the off peak hours?

determine observance of, and suitability of, existing speed limits

establish maximum and minimum speed limits

provide information for use in road safety and enforcement programs

establishment of no-passing zones

assist the location of certain traffic signs (speed signs)

Uses of Spot Speed Data (5)

Select the leading vehicle or different vehicles in the platoon

As much as possible, conduct proportional sampling (more passing trucks means more trucks to be included in the sampling)

Vehicles should be selected randomly from the traffic stream

Things to do to avoid errors during spot speed study (3)

Time vs Measured Distance

Distance vs Measured Time

Radar Meters

Methodology for Spot Speed Studies (3)

TIME VS MEASURED DISTANCE

Measurement of the time required for a vehicle to traverse a measured course or "trap"

Manual (stopwatch), electromechanical or mechanical means

Time can be measured with what? (3)

88ft or 30m

Recommended trap length for an average speed of less than 40 kph of the traffic stream?

176 ft or 55m

Recommended trap length for an average speed of more than 40 kph but less than 64 kph of the traffic stream?

264 ft or 80m

Recommended trap length for an average speed of more than 64 kph of the traffic stream?

DISTANCE VS MEASURED TIME

Commonly used in photographic studies

DISTANCE VS MEASURED TIME

In this method, cictures of traffic are taken at precise intervals

RADAR METERS

Using a radio wave that is reflected from a moving target. The frequency changes in proportion to the speed of the target

TRAFFIC VOLUME

number of vehicles that pass a given point on a road, or a given lane or direction of a road, during a specified time interval

Vehicle per day (veh/day, vpd)

Vehicle per hour (veh/hr, vph)

Units of Traffic Volume (2)

VOLUME MAP

DESIRE LINE DIAGRAMS

JUNCTION/INTERSECTION TURNING MOVEMENTS

Presentation of Traffic Volume Data (3)

VOLUME MAP

maps of traffic volumes with a geographical background overlaid by bandwidths representing traffic volumes

DESIRE LINE DIAGRAMS

volume maps wherein the bandwidths connect planning zone centroids in the network

Volume Map

macro level of presenting traffic volume data

Desire Line Diagram

presentation of traffic volume data that requires origin to origin trips

Intersection Turning Movements

micro level of presenting traffic volume data

TRAVEL TIME STUDIES

Determine the time required to traverse a specific route or section of a road

travel time and travel speed

output of travel time studies

DELAY STUDIES

Provide information on the amount, cause, location, duration and frequency of delays as well as travel time

TRAVEL TIME

Total elapsed time of travel, including stops and delay, necessary for a vehicle to travel from one point to another

RUNNING TIME

Portion of the travel time that the vehicle is actually in motion

travel time - stopped time delay

formula for running time

RATE OF MOTION

Travel time expressed in terms of min/mile or min/km

TRAVEL SPEED

Overall average speed along a specified section of road

total distance/travel time

formula for travel speed

RUNNING SPEED

average speed along a specific route when the stopped time is removed from the computations

DELAY

Time lost by traffic due to traffic frictions and traffic control devices

TRAVEL TIME DELAY

Difference between the actual time required to traverse a section of road and time corresponding to the average speed of traffic at a point of non-congested flow on the section

STOPPED TIME DELAY

The time a vehicle is actually standing still in traffic

Public Utility Vehicle Loading/Unloading

Meaning of (1) for Cause of Delay

Stop Sign/Red Signal at Intersection

Meaning of (2) for Cause of Delay

Pedestrian Crossing

Meaning of (3) for Cause of Delay

Maneuvering vehicles

Meaning of (4) for Cause of Delay

Blocked by other vehicles

Meaning of (5) for Cause of Delay

Road construction/maintenance

Meaning of (6) for Cause of Delay

others

Meaning of (7) for Cause of Delay

PARKING STUDIES

Are designed to identify inadequacies in the supply of parking lots, or to determine existing demand.

ACCIDENT STUDIES

It is undertaken usually after several accidents have happened in a specific road strip/road length.

road safety audit

conducted as part of accident studies

Signs are placed in proper locations

Pavement marking are provided in road strips where sight distance is obstructed

Road safety audits check whether (2):

ORIGIN-DESTINATION SURVEY

Roadside interview survey to establish trip patterns based on vehicle type, trip purpose, and sometimes even vehicle occupancy

ORIGIN

Place where the surveyed motorist came from on the current trip

DESTINATION

place where the surveyed motorist is heading to on the current trip

To determine the existing traffic trip patterns

To determine the traffic percentages coming from each zones

To forecast future trip patterns of each vehicle type

USED OF O-D SURVEY (3)

Along highways near the concerned road intersection

Where are O-D surveys usually established?

Tuesdays, Wednesdays, and Thursdays

Days when O-D surveys are usually conducted to avoid abnormalities within the data set

6:00 AM to 6:00 PM

Usual time period for O-D survey

As much as possible, conduct proportional sampling (more passing trucks means more trucks to be included in the sampling)

Vehicles should be selected randomly from the traffic stream

Road side survey should be performed with a minimum number per hour

Asks clearly, politely, and concisely during the interview

Things To Do to Avoid Errors During O-D Survey (4):

Tricycle

Motorcycle

Passenger car

Passenger utility

Goods utility

Small bus

Large bus

Rigid truck 2-axles

Rigid truck 3+ axles

Semi trailer trucks 3/4 axles

Semi trailer trucks 5+ axles

Trailer trucks 4-axles

Trailer trucks 5+ axles

Vehicle Types to be Surveyed (13)

WORK

O-D Survey Trip Purpose: Heading to and from workplace

SCHOOL

O-D Survey Trip Purpose: Students, Shuttle service to School

BUSINESS

O-D Survey Trip Purpose: Deliveries of goods, materials, or services (consulting, labor works, etc.)

PRIVATE MATTER

O-D Survey Trip Purpose: Visits to relative, friends, love ones, and personal trips

OTHER

O-D Survey Trip Purpose: other purpose not listed above

Station Name (OD 1, OD 2, OD n)

Project Name

Location (Road Name, barangay, and Municipality)

Sketch of survey location (for reference during analysis)

Direction of travel (came from and heading to)

Time (1 hour aggregation) may be further related to trip purpose

Date of Survey

Name of interviewer

Other Necessary Information for O-D Survey (8)

HIGHWAY CAPACITY

No. of vehicles that a highway can effectively accommodate. It can be per lane, per direction of travel, or for both direction of travel

Number of lanes

Lane widths

Shoulder widths and lateral clearances

Design Speed

Type of facility (road type)

Horizontal and vertical alignment (curves along the lateral and vertical movement of the highway)

factors can influence the capacity of a road (6)

1,800 to 2,400 pcu/hr

The required capacity of a two-lane, two-way road from both directions assuming adequate lane widths

URBAN ROADS

These roads tend to have less control on the number of access points per kilometer.

URBAN ROADS

Design Speed for this type of roads usually ranges between 20-40 km per hour.

URBAN ROADS

Pedestrian activity as well as parking activity are comparatively higher compared to other road types.

HIGHWAYS

Roads that cater large volume of traffic in longer distances compared to urban roads.

HIGHWAYS

Can be considered as arterial roads in local setting.

HIGHWAYS

Traverses multiple cities, municipalities, and in some cases regions.

HIGHWAYS

Design Speed for this type of roads usually ranges between 40-80 km per hour.

HIGHWAYS

Pedestrian activity as well as parking activity are controlled.

2-lane Highway

4-lane Highway

Divided Highway

Types of Highways (3)

2-lane Highway

Has a single lane per direction of travel.

4-lane Highway

Has 2 directional traffic flow with 2 lanes per direction and passing is accomplished on lanes not subject to use by opposing traffic.

Divided Highway

Has 2 directional traffic flow with a minimum of 1.2m median and it has at least two full lanes.

NATIONAL ROAD

Public roads declared as national roads by the President of the Philippines

Primary Road and Secondary Road

further classification of national road

Min RROW : 20.0 m

Min Width : 6.7 m

Max Allowable Grade : 6%

Min RROW and Width, Max Grade of National Road

PROVINCIAL ROAD

Roads that connect one municipality to another

Min RROW : 15.0 m

Min Width : 6.1 m

Max Allowable Grade : 6%

Min RROW and Width, Max Grade of Provincial Road

CITY ROAD

Roads or streets within the urban area of a city not classified as provincial or national road

Min RROW : 15.0 m

Min Width : 6.1 m

Max Allowable Grade : 6%

Min RROW and Width, Max Grade of City Road

MUNICIPAL ROAD

Roads or streets within the poblacion area of a municipality not classified as provincial or national road

Min RROW : 15.0 m

Min Width : 6.1 m

Max Allowable Grade : 6%

Min RROW and Width, Max Grade of Municipal Road

BARANGAY ROAD

Roads located outside the poblacion area of a municipality or urban area of a city and those outside industrial, commercial or residential subdivision and those which act as a feeder to farm-to market roads

Min RROW : 10.0 m

Min Width : 4.0 m

Max Allowable Grade : 10%

Min RROW and Width, Max Grade of Barangay Road

TOURISM ROAD

Roads which marketed as particularly suited for tourists

Min RROW : 2.1 m

Min Width : 6.0 m

Max Allowable Grade : 6%

Min RROW and Width, Max Grade of Tourism Road

FARM-TO-MARKET ROAD

Roads linking the agriculture and fisheries production sites, coastal landing points and post harvest facilities to the market and aerial roads

Min RROW : 6.0 m

Min Width : 4.0 m

Max Allowable Grade : 10%

Min RROW and Width, Max Grade of Farm to Market Road

INTERSECTION

General area where two or more highways join or cross. For two or more directional traffic, perpendicular intersections are the most desirable.

At-Grade Intersection

Grade Separated Intersection

Interchange

Types of Intersection (3)

AT-GRADE INTERSECTION

The adjoining roads in a highway intersection exist in the same road level (1st level and 1st level)

When vehicular traffic volume is below the intersection capacity

When we want to provide access to new adjoining road

When changing direction of travel with multiple destination options.

Usually used for roads within cities and municipalities

When/Where to use At-grade Design Intersection (4)

GRADE SEPARATED INTERSECTION (WITHOUT RAMPS)

The adjoining roads in a highway intersection exist on different road levels (1st level and 2nd level).

GRADE SEPARATED INTERSECTION (WITHOUT RAMPS)

With this type of intersection, greatest efficiency, safety, capacity can be attained.