1. I-84 Baker Valley Variable Speed Limit System
Lessons learned
Intelligent Transportation System June, 2017

2. Baker Valley VSL
System overview

3. ATM Overview
Congestion and weather responsive systems operate simultaneously with slower speed conditions taking priority.

4. Signs and Messages
These photos are just examples. Please replace photos with your own.

5. Monitoring Equipment
Each RWIS location is comprised of a pavement sensor, air temperature/relative humidity sensor, traffic sensor, and a camera.

6. DSC/DST-111 Pavement Sensors
Temperature sensors and cameras are added to all pavement sensor locations to validate readings.

7. Baker Valley ATM Operations
November April 2017
Segment
Override Count
Weather Reduction Count
Hours with Speed Reduction
I-84 EB Baker ( ) 56
106
551
I-84 EB Clover ( ) 87
139
752
I-84 EB Medical ( ) 62
149
577
I-84 WB Baker ( ) 55
104
568
I-84 WB Clover ( ) 91
150
775
I-84 WB Medical ( ) 61
115
561

8. Project Design Criteria
These photos are just examples. Please replace photos with your own.
No guardrail to avoid snow drifts. All structures outside the clear zone.
Signs over the travel lanes vs. roadside for traffic & snowplow operations.

9. Maintainability Minimize parts in sign housing
LED board replacement requires lane closure

10. DSC/DST-111 Pavement Sensors
Pavement sensors experience loss of signal during low visibility conditions and report “Other” for grip factor and visibility.

11. ATM Changes

12. DSC/DST-111 Pavement Sensors
Snow covers only one lane causing a difference of pavement friction from one lane to the next.

13. ATM System averaged on ramp speeds with mainline
Traffic Module
Baker Valley Rest Area On Ramp
ATM System averaged on ramp speeds with mainline
Lower average speeds caused speed reduction on signs

14. Planned Baker Valley Changes
Adding additional DSC/DST-111 sensors to monitor the A lane.
Adding camera with IR emitter.
Relocating DSC/DST-111 sensors half a mile at the request of the District to detect weather more representative of the corridor.
Adding guardrail to protect the sign structures at the request of the Region Manager.

15. Baker Valley System ATM Configuration

16. ATM Changes
The weather response condition table was increased to incorporate all possible sensor threshold combinations.
Rest area on-ramp lane was removed from the sensor collection to stop speed reductions in ATM congestion response.
The signs were initially configured to default to 70 or Trucks 65 during communication outages. Changed to default to blank.
Pavement condition “Other” added to weather response condition table due to visibility issue.

17. ATM Changes Adding a second threshold for grip factor and visibility.
Adding additional speed reduction tables to address two pavement sensors at the same location.

18. Concept of Operations Changes
OAR requires STE approved VSL algorithm.
The weather response speed lookup tables were updated to incorporate the air temperature threshold and “Other” surface condition.

19. Concept of Operations Changes
These photos are just examples. Please replace photos with your own.
Speed lookup tables were updated with graphics of the sign renderings.
The manual override speed conditions and responses table was updated to incorporate the 70 MPH speed zones.

20. Concept of Operations Changes

21. Concept of Operations Changes

22. Concept of Operations Changes

23. Concept of Operations Changes

24. Manual Operation

25. Manual Operation

26. Law Enforcement Coordination
New section title slide option 1

27. Law Enforcement
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28. CAD Integration

29. Mt Hood Advisory Speed System
Joint project with Region 1 and 4.
Project started Design started before Baker Valley VSL project.
Design delayed due to USFS permitting and visual impact concerns.

30. Mt Hood Advisory Speed System

31. US97 Variable Speed Limit System
These photos are just examples. Please replace photos with your own.

32. I-84 Snow Zone Safety Improvements
New section title slide option 1

33. DSC/DST-111
Shorter beam and steeper angle is needed to reduce loss of signal condition during low visibility conditions.
ITS needs to develop long term contract solution for grip factor sensors.

34. Visibility
ITS is considering using traditional forward scattering optical sensor for visibility instead of DSC Comparison testing for next winter.
Agenda slide option 2

35. Structures
ITS is working with Traffic HQ to update VMS standard drawings for monotube cantilever, similar to Colorado DOT.

36. Thank you.