`CE 452
Road Traffic Studies
Tasks:
1.
2.
3.
4.
Traffic volume study (Mirpur Road)*
Traffic speed study (Mirpur Road) *
Road condition survey (Mirpur Road)
Bus franchise before-after study (Azimpur to Uttara)
* Will be based on Video data collected
Data collection:
Primarily on Thursday (April 30), 8:00am – 10:30am
Each group will arrange convenient times for processing the data
Submission Dates:
Class 6: No Lectures
Class 7: Submission and presentation of Assignment 1 and 2
Class 8: Data collection for Bus Franchise after study (Assignment 4)
Class 9: No Lectures
Class 10: Submission and presentation of Assignment 3 and 4
Submissions will include individual reports and involve group presentations.
General Note:
The data collection for Assignments 1-3 will be done simultaneously. Plan first who is
going to be responsible for which task.
These are open ended assignments. We have mentioned the mandatory analysis in the
subsequent pages. But you are free to choose your form of presentation (e.g. table, chart,
graph, pictures etc.). You are also encouraged to present additional analysis related to the
assignments.
If you have any questions, please check with the course teachers.
Assignment 1
Traffic Volume Study
Objective:
Measure traffic volumes and note other related traffic characteristics (e.g. flow
composition, spatial fluctuation etc.).
Data Collection
 Based on video recordings from foot over-bridge
 Observation: Classified vehicle counts
 Method: Manual counts from video recording
 Location: Mid-block
 Duration: 30 mins effective duration (record at least 45 mins in total)
 Sampling: None (count all vehicles)
Tips
Before data collection
 Find the most suitable position for observation (e.g. location in the foot overbridge that allows optimum coverage)
After data collection
 Perform a trial survey to familiarize with the job and identify any problems in
vehicle counting (e.g. clarify definition of vehicle classes, allocate responsibilities
to the group members, etc.)
Data Analysis
 Estimate ADT based on expansion factors
 Determine service flow rate in PCU/PCE unit
 Determine vehicle composition in traffic stream
 Draw flow fluctuation curves (combining data from other groups)
Assignment 2
Traffic Speed Study
Objective:
Measure the spot speed and travel speed of vehicles and note other related traffic
characteristics.
A. Spot Speed
Data Collection
 Based on video recordings from foot over-bridge
 Observation: Record travel times within a small strip of known length.
(Recommended strip lengths: <25 mph: 88ft; 25-40 mph: 176ft; >40 mph: 264ft)
 Method: Manual data transcription based on video recordings
 Location: Mid-block
 Duration: 30 mins effective duration
 Sampling: None (count all vehicles)
Tips
Before data collection
 You can use the same video footage as in Assignment 1
 Select two prominent objects (e.g. lamp posts, poles etc.) to mark the strip and
accurately measure the distance. It may be more convenient to use ranging rods to
mark the starting and ending points of the strip.
 Perform a trial survey to familiarize with the job
After data collection
 Perform a trial survey to familiarize with the job and identify any problems in
vehicle counting (e.g. clarify definition of vehicle classes, allocate responsibilities
to the group members, etc.)
B. Travel Speed
Data Collection
 Based on video recordings from foot over-bridge
 Observation: Travel time between two widely separated sections
 Method: Manual data transcription based on video recordings. You need to
combine data from different groups and match the vehicles. Ensure that the
times in all the cameras match with each other.
 Duration: 30 mins effective duration
(the first few minutes of the data from the end cameras in each direction will not
be useful since the measure of interest is the time each of the through vehicles
need to traverse the entire length covered by the three cameras.)
 Sampling: None (count all vehicles)
Tips
Before data collection
 You can use the same video footage as in Assignment 1

Similar to spot speed study, select two prominent objects (e.g. lamp posts, poles
etc.) to mark the points between which travel times will be measured. Accurately
measure the distance. It may be more convenient to use ranging rods to mark the
starting and ending points.
After data collection
 Prepare a data sheet to enter vehicle type and assign numbers for your reference
(note: license plate numbers will not be visible to you as in manual survey).
Allocate responsibilities to group members. Recheck to ensure accuracy. You
have the flexibility to rewind and forward the collected data !
Data Analysis
 Present detailed diagram of spot speed and travel speed calculation locations
(example in Figure 1)
 Calculate spot speeds
 Prepare tables for statistical analysis of spot speeds
 Plot histograms, frequency curves and Cumulative frequency curves of spot
speeds
 Determine weighted average speed. pace, modal speed, speed limits. design speed
etc. of spot speeds
 Check the spot speed distribution pattern by fitting a normal distribution curve
 Find Time-mean speed (TMS) and Space-mean speeds (SMS) using the travel
speed data
 Prove that: the SMS is lower than the TMS
 Verify the Wardrop relationship between TMS and SMS:
Vt  Vs 
 s2
Vs
Vt  sample TMS
Vs  sample SMS
 s2  var iance of sample SMS
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Calculate delay for each type of vehicle (assuming free flow spot speed as the
travel speed)
Find the delay cost based on vehicle occupancy rate, vehicle operating cost, value
of time (VoT) etc.
Discuss the other potential congestion costs
Draw speed-flow diagrams based on observed data
Superimpose with typical speed-flow relationship diagrams
Show different levels of service (LOS)
Find LOS of the studied road stretch.
Figure 1: Spot speed data collection setup
Assignment 3
Road Condition Survey
Data collection
Geometric Condition
 Observations
o Geometric layout of roadway (road length, width, number of lanes,
median height, width, shoulder height, width etc.)
o Geometric layout intersections (geometric measurement and positi0n of
channels/islands, corner radius, dimension and location of pedestrian
refuge) .
o Surface condition
.
 by skid resistance tester or sand-patch method in several locations
(near high speed location, zebra crossing, intersection)
 by qualitative observation of potholes, elevated/depressed
manholes, speed breakers etc.
o Equipment - Tape, Odometer etc.
Operating Condition
 Observations
o Location and width of side roads
o Road side land-use pattern
o Loss of road width due to parking, passenger load/unloading, presence of
dustbin/construction materials etc.
o Pedestrian crossing facilities
o Locations and type of control devices
 Road signs, markings
 Signal (per approach no. of signal, type of signal heads, especial
filter signal)
 Speed breakers
 Layout of street lighting system (spacing, pattern etc.)
Analysis
 Draw the detailed layout of roadway and intersection
 Show the location of bottlenecks (side road, parking, pedestrian concentrations,
dust bins, speed breakers etc.), street light arrangement, control devices etc.
 Determine
o Loss of effective width at different locations of road
o Average skid resistance value at different locations of road
o Density of road obstructions (potholes, elevated/depressed manholes,
speed breakers etc.)
o Density of side roads (access control)
 Identify road-traffic problems and suggest improvement measures
Lists of Tasks on Thursday
1. Selecting location and general planning (group decision)
2. Video recording (assign at least 2 students from each group to ensure safety of the
camera)
3. Geometric measurements (around 4 students from each group)
4. Spot speed measurement location identification with ranging rods (if needed)
5. Skid resistance measurement (