05 Traffic Data Collection (Traffic Engineering هندسة المرور & Prof. Saad AlGadhi)

1. CE 436 Traffic Engineering
Topic 5: Traffic Data Collection
Prof. Saad AlGadhi
CE 436 –Traffic Engineering
King Saud University
email: salgadhi@ksu.edu.sa

2. CE 436_KSU_Prof.AlGadhi
Traffic Studies (Ch. 8)
 A traffic engineer’s laboratory is the
surrounding roadway system
 This system must be continually
monitored, evaluated, and managed
2

3. CE 436_KSU_Prof.AlGadhi
Guiding Principles
 “If you cannot tell the system performance
yesterday, you cannot hope to manage your
system today.”
-- Data Collection/Analysis
 “Data are too valuable to only use once.”
-- Data Archive
-- Real Time and Historical
3

4. CE 436_KSU_Prof.AlGadhi
Traffic Studies
 Traffic demand/patterns will change
over time, monitoring of system will
enable necessary system changes to be
identified
 The effects of system “improvements”
must be justified, e.g.,
 Signal timing changes
 Lane additions or reconfigurations
4

5. CE 436_KSU_Prof.AlGadhi
Traffic Studies
 Data collection is the key foundation
 What kind of data?
 How much data?
 How to collect it?
 The study characteristics must be considered
in answering these questions, e.g.,
 Short-term or long-term study
 Statistical confidence level
5

6. Traffic Studies Reasons
 Managing the physical system
 Establishing time trends
 Understanding travel behavior
 Calibrating basic relationships or
parameters
 Assessing the effectiveness of
improvements
 Assessing potential impacts
 Evaluating facility or system performanceCE 436_KSU_Prof.AlGadhi 6

7. Traffic Studies Types
1. Volume studies
2. Speed Studies
3. Travel-time studies
4. Delay Studies
5. Density and Occupancy studies
6. Accident Studies
7. Parking studies
8. Goods Movement and transit studies
9. Pedestrian studies
10.Calibration studies
11.Observation/Compliance studiesCE 436_KSU_Prof.AlGadhi 7

8. Data Collection Methodology
 Manual:
 e.g., Intersection turning movements,
Vehicle Occupancy
 Can be supported by handheld devices
 Semiautomated:
 e.g. pneumatic road tubes & associated
recording devices.
 Fully automated:
 Permanent detectors and sensors.CE 436_KSU_Prof.AlGadhi 8

9. Figure 8.1 Hand Counters Illustrated
CE 436_KSU_Prof.AlGadhi 9

10. CE 436_KSU_Prof.AlGadhi
JAMAR Handheld Devices
10

11. CE 436_KSU_Prof.AlGadhi
Software Program
11

12. CE 436_KSU_Prof.AlGadhi
Expanding Short Counts (Table 8-1)
12

13. Figure 8.2 Parallax Error Illustrated (Speed Study)
CE 436_KSU_Prof.AlGadhi 13

14. Figure 8.3 Measuring Speeds with Radar Meters
CE 436_KSU_Prof.AlGadhi 14

15. Figure 8.4 Road Tubes with Portable Counter
CE 436_KSU_Prof.AlGadhi 15

16. CE 436_KSU_Prof.AlGadhi
Portable Road Tube Counter
16

17. Figure 8.6 Typical Installation of an Induction Loop Detector
CE 436_KSU_Prof.AlGadhi 17

18. CE 436_KSU_Prof.AlGadhi
Inductance Loops
18

19. CE 436_KSU_Prof.AlGadhi 19

20. CE 436_KSU_Prof.AlGadhi 20

21. CE 436_KSU_Prof.AlGadhi 21

22. Figure 8.7 Overhead Installation of a Permanent Microwave Radar Detector
CE 436_KSU_Prof.AlGadhi 22

23. Figure 8.8 Roadside Installation of Permanent Microwave Radar Detectors
CE 436_KSU_Prof.AlGadhi 23

24. Figure 8.9 An Overhead Laser Infrared Radar Installation
CE 436_KSU_Prof.AlGadhi 24

25. CE 436_KSU_Prof.AlGadhi
Video Imaging
25

26. CE 436_KSU_Prof.AlGadhi
Video Imaging
26

27. CE 436_KSU_Prof.AlGadhi
Video Imaging
27

28. Interview Studies
 Home Interviews
 Roadside Interviews
 Destination-based Interviews
CE 436_KSU_Prof.AlGadhi 28

29. CE 436_KSU_Prof.AlGadhi
Origin-Destination (O-D) Studies
29

30. CE 436_KSU_Prof.AlGadhi
O-D Measurement Techniques
 Roadside Interview
 Postcards
 License Plate Matching
30