1. Traffic Jamboree: Factors Contributing to Phantom Jams
Jamie Ye, Eva Reyes, Brooks Wilding, Jack Lance, Zack Shen, Benjamin Nesselrodt, Stefan Joseph

2. Classic Scenario
Stuck in a Jam? The Science behind Traffic. Digital Image. Evidence Based Living. Cornell University, n.d. Web. 29 July 2014

3. History Car industry revolutionized lives of Americans
Came with many negatives
Traffic rules and regulations evolved with growth of transportation industry
Greenshields study in 1930s
----- Meeting Notes (7/29/14 18:09) -----
Jamie

4. Why it Matters Cost Environment Public Health
----- Meeting Notes (7/29/14 18:09) -----
Jamie

5. Various Models Microscopic Car-Following Models Macroscopic Models
Gas-Kinetic Models
Cellular Automaton Models
----- Meeting Notes (7/29/14 18:12) -----
Eva

6. Nagel-Schreckenberg Freeway Traffic Four Steps Slow-to-Start Variant
----- Meeting Notes (7/29/14 18:12) -----
Eva

7. Car locations when vmax = 135 km/h, ρ = 8
Car locations when vmax = 135 km/h,  ρ = 8.67 cars/km, and prob(slow) = 0.5
Position (km)
7.5
5.0
2.5 25 50
Time (min)

9. Phase Diagram Intermediate Transition Points
Density (cars per kilometer)
Velocity (km/hr)

10. Combined Phase Diagram
Density (cars per kilometer)
Velocity (km/h) 80 60 40 20
P = 0.25
P = 0.50
P = 0.75

11. Maximum
Velocity
(km/h)

13. Maximum
Velocity
(km/h)

14. Highway Density
(cars/km)

15. Maximum Velocity
(km/h)

16. Highway Density
(cars/km)

17. Slow-to-start model
Position (km)
Time (min)

18. Maximum Velocity
(km/h)

19. Highway Density
(cars/km)

21. Conclusions: The Five Commandments of Traffic Jams
1. Before vc , ρc : vmax  = flux , density  = flux  At or beyond vc , ρc : unstable, jams, variance 
2. For slow-to-start vc ≈ 180 km/h for all ρ, so for vmax < vc : vmax  = flux 
3. Pushing vmax to unrealistic levels (>200 km/h): no benefit

22. The Five Commandments of Traffic (continued)
4. As P(slow) increases, vmax and ρ show less effect on flux
5. vmax has no apparent effect on speed of jam propagation

23. Relevance 20 40 60 80 100 120 London M25 Motorway Boston
Combined Phase Diagram
Density (cars per kilometer)
Velocity (km/h) 80 60 40 20
P = 0.25
P = 0.50
P = 0.75
London
M25 Motorway
Boston
Central Artery/Tunnel Project

24. Sources
Stuck in a Jam? The Science behind Traffic. Digital Image. Evidence Based Living. Cornell University, n.d. Web. 29 July 2014
Hicks, Mark A. Stone Tablets – Clip Art Gallery. Digital Image. Stone Tablets – Clip Art Gallery. Discovery Education, n.d. Web 30 July 2014.

25. Acknowledgements Pennsylvania Governor’s School for the Sciences
Pennsylvania Department of Education
PGSS Corporate Sponsors: EQT, AT&T, Teva Pharmaceuticals, PPG, Alcoa, Westinghouse
PGSS Private Sponsors
PGSS Alumni Association and PGSS Campaign, INC.
Carnegie Mellon University
Pennsylvania Governor’s School for the Sciences
Dr. Barry Luokkala – PGSS Program Director
Melissa Lessure – Assistant to the Director
Zach McDargh – Team Project Advisor
Kaleigh Felisberto – Teaching Assistant
PGSS 2014 Teaching Assistants and Residence Life Directors

26. Thank You. Any Questions?