This document provides an overview of a traffic engineering course that discusses ramp metering. It covers the history of ramp metering, different types of ramp metering including local, traffic responsive, and coordinated ramp metering. It also outlines design methods for metered single and multi-lane entrance ramps. The document concludes with a case study on a ramp metering system implemented in Tehran, Iran which led to reductions in delay times and increases in highway speeds and traffic flow.

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?