1. BIHE University
Department of Civil Engineering
Traffic Engineering – CIV4116
July, 2012
Overview
Course: Traffic Engineering, CIV4116
Instructor: Mr. Peyman Misaghi
Date: Saturday, July 29, 2012
Spring 2012

2. Keywords
• Ramp
• Metering devices
• Algorithm

3. Outline
• Introduction
• History
• Ramp Metering Algorithms
• Types of Ramp Metering
• Design Methods
• Case Study
• Conclusion

4. Introduction
• Definition
Metering Signal

5. Introduction (Cont’d)
• Most important pros
– Controlling traffic flow
– Break line between platoons
– Diverting to waiting route

6. History
• Eisenhower Expressway (I-290) in
Chicago, Illinois, in 1963.

7. Ramp Metering Algorithm
• System Architecture
– Release algorithm
– Switch on-off algorithm
– Ramp metering algorithm
– Queue override algorithm
– Queue management algorithm
– Data filtering algorithm

8. Types of Ramp Metering
• Local ramp metering
– Conventional type
– Basic design: Highway Capacity Manual
– Disadvantages
• Lack of data plan
• Forecasting

9. Types of Ramp Metering
(Cont’d)
• Local traffic responsive ramp metering
– Local data plan by detectors
– Lack of network plan
Mainline Upstream Detectors Mainline Downstream Detectors
Demand Detector
Merge Detector
Warning Sign/Signal
Metering Signal
Frontage Road
Advanced Queue Detector

10. Types of Ramp Metering
(Cont’d)
• Coordinated Ramp Metering
– Data plan for the whole system
– Best and most expensive!
– Transportation Management Center (TMC)

11. Types of Ramp Metering
(Cont’d)
• Coordinated Ramp Metering
Seattle: 126
Minn-St. Paul: 430
Portland: 110
Milwaukee: 122
Chicago: 117 New York: 75
Salt Lake
City: 23
Denver: 46
N. Virginia: 26
LA: 1478
Phoenix: 122
Arlington: 5
Implemented
In Progress

12. Design Methods
• Ramp Meter Design Manual
[Traffic Operation Programs]
A. Metered single-lane entrance ramps
B. Metered multi-lane entrance ramps
C. Metered freeway-to-freeway connections
…

13. Design Methods (Cont’d)
A. Metered single-lane entrance ramps

14. Design Methods (Cont’t)
• Association to other transportation
management system:
– HOV lanes
– Carpools
– Transit riders
– etc

15. Design Methods (Cont’t)
• HOV lane [Not Metered]

16. Design Methods (Cont’t)
• HOV lane [Metered]

17. Case Study
• Ramp Metering System in Tehran
Highways and Algorithm Customizing
– Amirkabir University of Technology
– Yadegar and Sheikh Fazlallh ramps in Hakim and
Hemmat highways from West to East

18. Case Study (Con’t)
Table 2 – Defined scenario for volume control
Scenario Name Cycle length Green time [sec]
1 … Hakim East 60 25
2 … Hakim East 90 45
3 … Hemmat – East 90 45
Table 3- Improvements in Highways
Name Yadegar-Hakim Sheikh…-Hakim Sheikh…-Hemmat
Delay - 7.2 7.9
Highway Speed 2.6 5.4 2.8
Travel Time - 5.8 13.2
Traffic Flow - 3 0.6

19. Conclusion
• Ramp metering advantages
• Application in USA
• Application in Iran

20. Any Question?