Why the extra RED LIGHT on freeway ramps?

All you want to do is get on the freeway. Then a seemingly superfluous traffic signal stops you. Do ramp meters work?

Buy me tacos 😀🌮►   / roadguyrob  
Ask a road question ► https://www.roadguyrob.com/interchange

-------------------------------
Additional reading:
-------------------------------
"Ramp Metering: A Proven, Cost-Effective Operational Strategy—A Primer," Federal Highway Administration
https://ops.fhwa.dot.gov/publications...

"Ramp Meters," Wikipedia
https://en.wikipedia.org/wiki/Ramp_meter



"Cost Estimates for ITS Devices of the T-REX Project" Summary, US Dept. of Transportation, 11/2001
https://www.itskrs.its.dot.gov/its/be...


"The Minimum Yellow Timing for Ramp Meters," Wang, Liu
https://www.sciencedirect.com/science...

"Case Studies of U.S. Freeway-to-Freeway Ramp and Mainline Metering and Suggested Policies for Washington State," Jacobson, Landsman
http://onlinepubs.trb.org/Onlinepubs/...

"A Case for Freeway Mainline Metering," Habobian
http://onlinepubs.trb.org/Onlinepubs/...

-------------------------
Time sections:
-------------------------
Introduction: (0:00)
Traffic Flow Fundamentals: (2:15)
Ohm's Law: (3:23)
Platoons and Shocks: (5:19)
Traffic Responsive Mode: (7:26)
Greenshields' Model: (10:19)
Effectiveness: (12:21)
Freeway-to-Freeway: (13:21)
Conclusion: (14:02)