The Transportation Systems Control Laboratory focuses on the development of traffic management techniques that utilize concepts in control and estimation theory in order to make more efficient use of existing highway facilities, and to reduce freeway congestion during commute periods.

The research has benefited from the support of Partners for Advanced Transit and Highways (PATH), a collaborative program between UC Berkeley and the California Department of Transportation (Caltrans). The laboratory has an ongoing relationship with Caltrans District 7 (Los Angeles and Ventura counties), which has an interest in projects that will provide enhanced service to their highway users. Examples of current projects and recently completed projects include: development of freeway on-ramp metering control and optimization algorithms, traffic flow modeling / identification / estimation, traffic simulation at the microscopic (vehicle-based), macroscopic (continuum-based), and hybrid (micro/macro) levels, and design and analysis of Automated Highway Systems (AHS).

Software tools have been developed to facilitate all of these endeavors. The research team has acquired many years' experience using the well-known microsimulator, VISSIM, and has applied it to test traffic control strategies.

Student list:
Current students:
Laura Munoz, Xiaotian Sun, Shantisa Norman, Sing Yiu Cheung, Denis Jacqunt

Former students:
Gabriel Gomes, Luis Alvarez, Jingang Yi, Sara Cinnamon, Xavier Claeys, Carla Guzman, Kevin Leung, Perry Li, Siddharth Patel, Dengfeng Sun, Joe Tan, Charmaine Toy

Publications:
Refereed Archival Journals:
J. Frankel, L. Alvarez, R. Horowitz, and P. Li, "Safety-Oriented Maneuvers for IVHS," Journal Vehicle Systems Dynamics, Vol. 26, No 4, , pp. 271-299, October 1996.

P. Li, R. Horowitz L. Alvarez, J. Frankel and A. M. Robertson, "An AHS Link Layer Controller for Traffic Flow Stabilization," Transportation Research Part C: Emerging Technologies, Vol. 5, No. 1, pp. 11-37, 1997.

P. Li, L. Alvarez and R. Horowitz "AVHS Safe control laws for platoon leaders," IEEE Transactions on Control Systems and Technology, Vol. 5, No. 6, pp. 614-628, 1997.

L. Alvarez and R. Horowitz "Safe Platooning in Automated Highway Systems. Part I: Safety Regions Design," Vehicle System Dynamics Special Issue: IVHS, Vol. 32, No. 1, pp 23-56, July 1999.

L. Alvarez and R. Horowitz "Safe Platooning in Automated Highway Systems. Part II: Velocity Tracking Controller," Vehicle System Dynamics Special Issue: IVHS, Vol. 32, No. 1, pp 57-84, July 1999.

L. Alvarez, R. Horowitz and P. Li. "Traffic Flow Control in Automated Highway Systems," IFAC Journal of Control Engineering Practice, vol. 7, no. 9, pp.1071-8, Sept. 1999.

R. Horowitz, and P. Varaiya, "Control Design of an Automated Highway System." Proceedings of the IEEE: Special Issue on Hybrid Systems, vol.88, no.7, pp. 913-25, July 2000.

Toy, C.; Alvarez, L.; Horowitz, R. "Nonstationary velocity profiles for emergency vehicles on automated highways." Journal of Dynamic Systems, Measurement and Control. vol.124, no.1, March 2002, pp.133-40.

Yi, J.; Alvarez, L.; Horowitz, R. "Adaptive emergency braking control with underestimation of friction coefficient." IEEE Transactions on Control Systems Technology, vol.10, (no.3), pp.381-92, May 2002.

C. Toy, K. Leung, L. Alvarez and R. Horowitz. "Emergency Vehicle Maneuvers and Control Laws for Automated Highway Systems," IEEE Transactions on Intelligent Transportation Systems. Volume 3, No. 2, pp.109-19. June 2002.

Yi, J.; Alvarez, L.; Claeys, X. and Horowitz, R. "Emergency Braking Control with an Observer-Based Dynamic Tire/Road friction Model and Wheel Angular Velocity Measurement." Vehicle System Dynamics, Vol. 39, No. 2, pp. 81-97, 2003.

J. Yi, H. Lin, L. Alvarez and R. Horowitz. "Stability of Macroscopic Traffic Flow Modelling Through Wavefront Expansion." Transportation Research Part B: Methodological, 37 (2003) pp. 661-679, 2003.
Refereed Conference and Symposium Proceedings:

P. Li, R. Horowitz, L. Alvarez, J. Frankel, and A. Robertson, "Traffic Flow Stabilization," Proceedings of the 1995 American Control Conference, pp. 144-149, Seattle, WA, June 1995.

J. Frankel, L. Alvarez, R. Horowitz, and P. Li, "Safety-Oriented Maneuvers for IVHS," Proceedings of the 1995 American Control Conference, pp. 668-672, Seattle, WA, June 1995.

P. Li, R. Horowitz, L. Alvarez, J. Frankel, and A. Robertson, "Traffic Flow Stabilization," SAE Systems and Issues in ITS, pp. 45-52, June 1995.

L. Alvarez, R. Horowitz and P. Li, "Link Layer Vehicle Flow Controller for the PATH AHS Architecture," Proceedings of the 1996 IFAC World Congress, Vol. Q, pp.207-212, San Francisco, July 1996.

P. Li, L. Alvarez, R. Horowitz, P.Y. Chen and J. Carbaugh, "A Safe Velocity Tracking Controllers for {AHS} Platoon Leaders," Proceedings of the IEEE International Conference on Decision and Control, pp. 2283-2288, Kobe, Japan, December 1996.

L. Alvarez, R. Horowitz and P. Li, "A Vehicle Flow Controller for AHS," Proceedings of the IEEE International Conference on Decision and Control, pp. 2295-2300, Kobe, Japan, December 1996.

P. Li, L. Alvarez and R. Horowitz, "AVHS Safe Control Laws for Platoon Leaders," Proceedings of 1996 ASME IMECE, Dynamics System and Control Division, pp. 9-16, November 1996.

L. Alvarez and R. Horowitz, Hybrid Control Design for Safe Maneuvering in the PATH AHS Architecture Proceeding of the American Control Conference, Albuquerque, NM, pp 2454-2459, June 1997.

L. Alvarez and R. Horowitz, Analysis and Verification of the PATH AHS Coordination-Regulation Layers Hybrid System Proceeding of the American Control Conference, Albuquerque, NM, pp 2460-2462, June 1997.

L. Alvarez and R. Horowitz, "An activity based traffic flow controller for AHS," Proceedings of the 1997 IEEE Conference on Decision and Control (CDC), San Diego, CA, pp. 1062-1067, Dec. 1997.

L. Alvarez, R. Horowitz, S. Chao and G. Gomes, "Optimal Desired Traffic Flow Patterns for Automated Highway Systems," Proceeding of the American Control Conference, pp. 1828-1832, Philadelphia, Pennsylvania, June, 24-26, 1998.

C. Toy, K. Leung, L. Alvarez and R. Horowitz. "Emergency Vehicles Maneuvers and Control Laws for Automated Highway Systems". Proceedings of the 1998 ASME IMECE. pp.705-12. December 1998.

C. Toy, L. Alvarez and R. Horowitz, A Traffic Flow Controller for Non-Stationary Velocity Profiles in Automated Highway Systems. Proceeding of the American Control Conference, pp. 3691-3696, San Diego, CA, June, 2-4, 1999.

C. Canudas de Wit and R. Horowitz "Observers for tire/road contact velocity using only wheel angular velocity information," Proceeding of the 38th IEEE Conference on Decision and Control, Part vol.4, 1999, pp.3932-7 vol.4. December, 1999.

Canudas de Wit, C., Horowitz R., Tsiotras P. "Model-based observers for tire/road contact friction prediction." In New Directions in Nonlinear Observer Design (Lecture Notes in Control and Information Sciences Vol.244). Springer-Verlag London. 1999, pp.23-42. London, UK.

L. Alvarez, J. Yi and R. Horowitz. "Emergency Braking in Automated Highway Systems with Underestimation of the Friction Coefficient." Proceedings of the American Control Conference, pp. 574-579. Chicago, IL, June 28-30, 2000.

G. Gomes, L. Alvarez and R. Horowitz. "Traffic Flow Patterns in AHS Networks: System and User Optimal". Proceedings of the American Control Conference, pp. 1498-1502. Chicago, IL, June 28-30, 2000.

J. Yi, L. Alvarez, R. Howell, R. Horowitz and J.K. Hedrick. "A Fault Management System for Longitudinal Control in AHS". Proceedings of the American Control Conference, pp. 1514-1518. Chicago, IL, June 28-30, 2000.

J. Yi, L. Alvarez and R. Horowitz, C. Canudas de Wit. "Adaptive Emergency Braking Control Based on a Tire/Road Friction Dynamic Model," Proceedings of the 39th Conference on Decision and Control. p.456-61 vol.1. Sidney, Dec. 2000.

Jingang Yi; Alvarez, L.; Claeys, X.; Horowitz, R.; Canudas de Wit, C. "Emergency braking control with an observer-based dynamic tire/road friction model and wheel angular velocity information." Proceedings of the 2001 American Control Conference, p.19-24 vol.1. Arlington, VA, USA, 25-27 June 2001.

Alvarez, L.; Jingang Yi; Horowitz, R.; Olmos, L. "Observer based emergency braking control in automated highway systems." Proceedings of the 2001 American Control Conference, p.2093-8 vol.3. Arlington, VA, USA, 25-27 June 2001.

Gomes, G.; Munoz, L.; Jingang Yi; Toy, C.; Cinnamon, S.; Horowitz, R.; Alvarez, L. "Meso-microscale traffic simulation of an AHS control architecture." Proceedings of the 2001 American Control Conference, p.1806-11 vol.3. Arlington, VA, USA, 25-27 June 2001.

Claeys X, Jingang Yi, Alvarez L, Horowitz R, Canudas de Wit C., Richard L. "Tire friction modeling under wet road conditions." Proceedings of the 2001 American Control Conference. IEEE. Part vol.3, June 2001, pp.1794-9 vol.3.

Claeys, X.; Yi, J.; Alvarez, L.; Horowitz, R.; Canudas de Wit, C. "A New 3D dynamic Tire/Road Friction Model for Vehicle Control and Simulation." Proceedings of the 2001 ASME IMECE, IMECE2001/DSC-24528, New York, November 11-16, 2001.

Xavier Claeys; Jingang Yi; Alvarez, L.; Horowitz, R.; Canudas de Wit, C. "A dynamic tire/road friction model for 3D vehicle control and simulation." Proceedings of the 2001 IEEE Intelligent Transportation Systems. Proceedings, p.483-8, Oakland, CA, USA, 25-29 Aug. 2001.

Munoz, L.; Gomes, G.; Jingang Yi; Toy, C.; Horowitz, R.; Alvarez, L. "Integrated meso-microscale traffic simulation of hierarchical AHS control architectures." Proceedings of the 2001 IEEE Intelligent Transportation Systems. Proceedings, pp. 82-7.Oakland, CA, USA, 25-29 Aug. 2001.

Jingang Yi, Hao Lin, Alvarez L, Horowitz R. "Stability of macroscopic traffic flow modeling through wavefront expansion." Proceedings of the 2002 American Control Conference Part vol.2, 2002, pp.1484-90 vol.2, June 2002.

L. Alvarez, J. Yi, R. Horowitz and L. Olmos, "Adaptive Emergency Braking Control With Observer-Based Dynamic Tire-Road Friction Model And Underestimation Of Friction Coefficient," Proceedings of the 15th Triennial World Congress of the International Federation of Automatic Control, Barcelona, Spain, July 21-26, 2002.

Jingang Yi and R. Horowitz. "Macroscopic traffic flow stability for adaptive cruise controlled (acc) vehicles." Proceedings of the 2002 Conference on Decision and Control (CDC). Part vol.1, 2002, pp.893-9. December 10 - 13, 2002.

Laura Munoz, Xiaotian Sun, Horowitz R. and Luis Alvarez. "Traffic density estimation with the cell transmission model." Proceedings of the 2003 American Control Conference. Denver Colorado. pp. 3750-3755, June 4-6, 2003.

Gabriel Gomes and Horowitz R. "A study of two onramp metering schemes for congested freeways." Proceedings of the 2003 American Control Conference. Denver Colorado. pp. 3756-3761, June 4-6, 2003.

Xiaotian Sun, Laura Munoz and Horowitz R. "Highway Traffic State Estimation Using Improved Mixture Kalman Filters for Effective Ramp Metering Control." Proceedings of the 42nd IEEE Conference on Decision and Control. Maui, Hawaii. December 9-12, 2003.

Xiaotian Sun, Horowitz R. and Chin-Woo Tan, "An Efficient Lane Change Maneuver for Platoons of Vehicles in an Automated Highway System." Proceedings of the ASME IMECE. Washington DC. November 15-21, 2003.

Gabriel Gomes, Adolf May and Horowitz R., "A Microsimulation Model of a Congested Freeway using VISSIM." Proceedings of the 83rd Annual Meeting of the Transportation Research Board, November 2003.

Laura Muñoz, Xiaotian Sun, Dengfeng Sun, Gabriel Gomes, and Roberto Horowitz. "Methodological calibration of the cell transmission model," in Proceedings of the 2004 American Control Conference, Boston, Massachusetts, June 30-July 2, 2004, pp. 798-803.

Xiaotian Sun, Laura Muñoz, and Roberto Horowitz, “Mixture Kalman filter based highway congestion mode and vehicle density estimator and its application,” in Proceedings of the 2004 American Control Conference, Boston, MA, Jun. 30-–Jul. 2, 2004, pp. 2098-–2103.

Luis Alvarez-Icaza, Laura Muñoz, Xiaotian Sun, and Roberto Horowitz. Ädaptive observer for traffic density estimation," in Proceedings of the 2004 American Control Conference, Boston, Massachusetts. June 30-July 2, 2004, pp. 2705-2710,

Gabriel Gomes and Roberto Horowitz. "Globally Optimal Solutions to the On-ramp Metering Problem - Part I," in Proceedings of the 7th International IEEE Conference on Intelligent Transportation Systems. 2004.

Gabriel Gomes and Roberto Horowitz. "Globally Optimal Solutions to the On-ramp Metering Problem - Part II," in Proceedings of the 7th International IEEE Conference on Intelligent Transportation Systems. 2004.

Xiaotian Sun and Roberto Horowitz, “Localized Switching Ramp-Metering Controller with Queue Length Regulator for Congested Freeways,” to appear in Proceedings of the 2005 American Control Conference, Portland, Or, Jun. 8-10, 2005.

Xiaotian Sun and Roberto Horowitz, “Localized Switching Ramp-Metering Control With Queue Length Estimation And Regulation And Microscopic Simulation Results,” to appear in Proceedings of the 16th IFAC World Congress, Prague, Czech Republic, July 4-8, 2005.

Book Articles:

C. Canudas-de-Wit, P. Tsiotras, X. Claeys, J. Yi, and R. Horowitz, "Friction Tire/Road Modeling, Estimation and Optimal Braking Control," in Nonlinear and Hybrid Systems in Automotive Control, Edit. R. Johansson and A. Rantzer, Springer Verlag,ISBN1-85233-652-8, 2003.

Non-refereed Conference and Symposium Proceedings:

L. Alvarez, P.Y.Li and R. Horowitz, "A link layer vehicle flow stabilizing controller for the PATH AHS control architecture," Proceedings of the 1996 Workshop on Adaptive Learning Systems. Yale, New Haven, July 1996. (Invited Paper).

L. Alvarez and R. Horowitz. "AHS Safe Feedback Based Maneuvers: A Design Approach for Hybrid Systems". Proceedings of the 1996 Cornell workshop on Hybrid Systems. 1996.

R. Horowitz, "Automatic Highway Systems; Proceedings of the 8th IFAC Symposium on Transportation Systems, June 1997, Chania, Greece. Part vol.2, 1997, pp.449-60 vol.2. (Plenary Talk).

L. Alvarez and R. Horowitz, "Traffic Flow Control in Automated Highways Systems," Proceedings of the 8th IFAC Symposium on Transportation SystemsPart vol.1, 1997, pp.65-70 vol.1. , June 1997, Chania, Greece.

Reports:

J. Frankel, L. Alvarez, R. Horowitz and P. Li, "Robust Platoon Maneuvers for AVHS," PATH Technical Note 94-9, November, 1994.

P. Li, R. Horowitz L. Alvarez, J. Frankel and A. M. Robertson, "An AVHS Link Layer Controller for Traffic Flow Stabilization," Institute for Transportation Studies, University of California at Berkeley. PATH Research Report, UCB-PATH TECH NOTE 95-15, May, 1995.

J. Frankel, L. Alvarez, R. Horowitz and P. Li, "Robust Platoon Maneuvers for AVHS," Institute for Transportation Studies, University of California at Berkeley. PATH Research Report, UCB-PATH TECH NOTE 94-09, May, 1995.

L. Alvarez and R. Horowitz, "Traffic flow control in automated highway systems," Institute for Transportation Studies, University of California at Berkeley. PATH Research Report, UCB-ITS-PRR 97-47, 1997.

L. Alvarez and R. Horowitz, "Safe platooning in automated highway systems," Institute for Transportation Studies, University of California at Berkeley. PATH Research Report, UCB-ITS-PRR 97-46, 1997.

P.Y. Chen , L. Alvarez and R. Horowitz, "Trajectory Design and Implementation of Longitudinal Maneuvers on AHS Automated and Transition Lanes," Institute for Transportation Studies, University of California at Berkeley. PATH Research Report, UCB-ITS-PRR 97-49, 1997.

J. Carbaugh, L. Alvarez, P.Y. Chen and R. Horowitz, "SmartPath Regulation Layer Implementation: A User's Guide," Institute for Transportation Studies, University of California at Berkeley. PATH Research Report, UCB-ITS-PRR 97-48, 1997.

D. Gulick, L. Alvarez and R. Horowitz, "Implementation of the regulation layer using Shift," Institute for Transportation Studies, University of California at Berkeley. PATH Research Report, UCB-ITS-PRR-98-26, 1998. (Formerly UCB-PATH TECH NOTE, 1997)

R. Horowitz, "Hybrid Supervisory Control for degraded Modes of Operation: Final Report for MOU135," PATH Research Report to CALTRANS 97-C19, 1997.

R. Horowitz, S. Sastry, P. Varaiya, L. Alvarez, K. Leung, C. Toy and D. Gulick , "Emergency vehicle Maneuvers and Control Laws for Automated Highway Systems," PATH Report to CALTRANS 98-C2, 1998.

Charmaine Toy, Kevin Leung, Luis Alvarez, Roberto Horowitz, "Emergency Vehicle Maneuvers and Control Laws for Automated Highway Systems". PATH Research Report UCB-ITS-PRR-2001-17, 2001.

Jingang Yi, Adam Howell, Roberto Horowitz, Karl Hedrick, Luis Alvarez, "Fault Detection and Handling for Longitudinal Control". PATH Research Report UCB-ITS-PRR-2001-21, 2001.

Jingang Yi, Shashikanth Suryanarayanan, Adam Howell, Roberto Horowitz, Masayoshi Tomizuka, Karl Hedrick, Luis Alvarez, "Development and Implementation of a Vehicle-Centered Fault Diagnostic and Management System for the Extended PATH-AHS Architecture: Part I". PATH Research Report UCB-ITS-PRR-2002-34, 2002.

Jingang Yi, Shashikanth Suryanarayanan, Adam Howell, Roberto Horowitz, Masayoshi Tomizuka, Karl Hedrick, Luis Alvarez, "Development and Implementation of a Vehicle-Centered Fault Diagnostic and Management System for the Extended PATH-AHS Architecture: Part II". PATH Research Report UCB-ITS-PRR-2002-35, 2002.

Roberto Horowitz, "Development of Integrated Meso/Microscale Traffic Simulation Software for Testing Fault Detection and Handling Algorithms in AHS: Final Report". PATH Research Report UCB-ITS-PRR-2003-13, 2003.