1. 3/29/06Michael Dixon1 CE 578 Highway Traffic Operations Lecture 28: Ramp Metering

2. 3/29/06Michael Dixon2 Objectives Terminology Objectives and types of ramp metering Local ramp metering Coordinated ramp metering

3. 3/29/06Michael Dixon3 Terminology Meter rate Allowable metering rate –MAX = 720 to 900 veh/hr –MIN = 180 to 240 veh/hr Vehicles per cycle (usually posted at meter)

4. 3/29/06Michael Dixon4 Ramp Metering Objectives and Types Local or coordinated Platoon-breakup Gap-acceptance Demand-capacity

5. 3/29/06Michael Dixon5 Local Ramp Metering—Platoon- Breakup

6. 3/29/06Michael Dixon6 Local Ramp Metering—Gap- Acceptance upstream gap detector detected gap vehicle released for gap

7. 3/29/06Michael Dixon7 Local Ramp Metering—Demand- Capacity mainline detector used to determine metering rate detected volume = 4800 vph Design capacity = 5400 vph Metered ramp upstream of potential bottleneck Allowed volume = 600 vph Meter rate of 600 vph or 6.0 seconds per vehicle.

8. 3/29/06Michael Dixon8 Coordinated Ramp Metering— Demand-Capacity General objective function

9. 3/29/06Michael Dixon9 Coordinated Ramp Metering— Demand-Capacity

10. 3/29/06Michael Dixon10 Coordinated Ramp Metering— Demand-Capacity

11. 3/29/06Michael Dixon11 Coordinated Ramp Metering— Demand-Capacity Setting meter rates

12. 3/29/06Michael Dixon12 Coordinated Ramp Metering— Demand-Capacity Choosing the next ramp to meter

13. 3/29/06Michael Dixon13 Coordinated Ramp Metering— Demand-Capacity bottleneck 12233445

14. 3/29/06Michael Dixon14 Coordinated Ramp Metering— Demand-Capacity Equation objective Second term Third term

15. 3/29/06Michael Dixon15 Coordinated Ramp Metering— Demand-Capacity