1. INCIDENT ANALYSIS USING PROBE DATA
Presented by: WG OLIVIER
Co-Authors: Dr. J Andersen & M Bruwer

2. Presentation Structure
Aim of research
Why do we need to investigate road incidents?
How incidents were investigated until now
What is probe data?
How is probe data used to investigate road incidents?
Results discussion
Conclusions and Recommendations

3. Aim of research
To propose a first of its kind, simple but accurate, method of determining the effect of a stationary truck on a freeway.
Adjacent Corridor
Immediate, surrounding network
To determine whether this methodology can accurately represent the true state of traffic on any given road.
Provided that enough data exist on the particular road for the different time sets.

4. Why do we need to investigate road incidents?
Increasing levels of congestion in cities around the world
Economic impact on companies delivering goods & services due to lost time in traffic
Freeway Management
Save lives
Frustration

5. How incidents were investigated until now
Mathematical Models and Simulations:
Extended Kalman Filtering Technique
Classification Models
Data Mining
Queueing Analysis etc.…
PROBLEM?
Many assumptions
Complex
Limited application
Time consuming
Often produce unreliable results

6. What is Probe Data?
Any travelling vehicle fitted with sensors = probe vehicle
The information collected from those sensors = probe data
Examples:
Global Positioning System (GPS)
Windshield Wiper status
Flat Tire
Airbag Deployment Status
Etc.
Focus on real-time historic probe data from TomTom

7. How is probe data used to investigate road incidents?
1. Custom Area Analysis (CAA)
Specify:
Boundary Box (Location)
Date Set (Day of the incident vs Typical)
Time Set (Duration of incident)
Obtain:
Approximate Area of Influence
Approximate Queuing Length

8. Probe Data use in incident analyses continued…
2. Custom Travel Time analysis (CTT)
Specify:
Route definition (Location)
Alternative route(s)
Date Set (Same as for CAA)
Time Set (Same as for CAA)
Obtain:
Segment-specific traffic data parameters
Average Travel Time
Average Speed
Cumulative Travel Time etc.

9. Summary of Methodology
Date
Location
Time Occured
Time Cleared
Incident Information
Network Impact
Queueing Length
CAA
Corridor impact
Alt-route impact
CTT

10. Incidents Analyzed STATIONARY TRUCKS Gauteng Incident
Location: N1 NB approximately 500 m before Garsfontein offramp (M30)
Date: Monday 25 January 2016
Duration: From 04:39 to 11:26 (6hr 47 mins)
Two out of four lanes were closed in the NB direction
2. Western Cape Incident
Location: R300 NB approximately 250 m before Van Riebeek offramp (R102)
Date: Monday 18 January 2016
Duration: From 07:04 to 08:48 (1hr 44 mins)
One out of three lanes were closed in the NB direction

11. Results Discussion
Custom Area Analysis

12. Results Discussion Continued…
2. Custom Travel Time: R300 NB
Increase between 08:00 and 09:00 from 10 minutes to nearly 17 minutes (70% increase)

13. Results Discussion Continued…
2. Custom Travel Time: R300 Alternative Route
Alternative route along Polkedraai Road, New Nooiensfontein Drive and Van Riebeek Road
14 minute increase

14. Results Discussion Continued…
3. Custom Travel Time: Cape Town R300 NB
Old Paarl Road
Van Riebeeck
Hindle Road
Polkedraai
Incident

15. Conclusions The methodology provided the results that were expected
The methodology has the ability to represent the true state of traffic during and after a non-recurrent incident event (stationary truck)
The methodology is easy to replicate, the results can be quickly produced and it is simple to interpret, unlike many other models
Major advantage: Work with real traffic data
no assumptions

16. Recommendations Further research is required on:
Different weather conditions
Other days of the week and times of the year
Unique or special events
Fatal crashes
A comprehensive benefit-cost analysis

17. END THANK YOU