Since the mid-1980s, transportation engineering faculty at the University of Florida (UF) have been working on developing state-of-the-art traffic analysis techniques and contributing to the Highway Capacity Manual (HCM), a publication used as a standard reference among transportation practitioners worldwide.  

“The contributions of the UFTI have been invaluable,” said Tom Creasey, chair of the Transportation Research Board’s (TRB) Highway Capacity and Quality of Service Committee (HCQSC). “Their studies have led to the development or the improvement of analytical methods that are in the Manual.” 

Several researchers at UF have worked toward the Manual’s methodology development throughout the years, such as Prof. Kenneth Courage, Dr. Lily Elefteriadou, Dr. Scott Washburn, Dr. Behzad Aghdashi, along with several staff and former students, including Dr. Seckin Ozkul, Dr. Alexandra Kondyli, Dr. Fabio Sasahara, Dr. Gustavo Andrade, Dr. Shen Dong, Dr. Yinan Zhang, Dr. Donald Watson, Dr. Zilin Bian, and Dr. Ehsan Amini. 

UF transportation faculty and researchers have also held leadership roles within the HCQS  full committee and its subcommittees, task forces, and working groups, including Prof. Ken Courage, Dr. Lily Elefteriadou, and Dr. Scott Washburn, former McTrans director Bill Sampson, Vishal Khanapure, Current McTrans Director Dr. Behzad Aghdashi, and Dr. Gustavo de Andrade.   

Dr. Elefteriadou, who is a professor of civil engineering and director of the University of Florida Transportation Institute (UFTI), served as the HCQSC chair from 2010 to 2016. She underscores the importance of having a Manual that provides consistent guidelines and computational procedures for practitioners. She says several current and former transportation students remain engaged with the HCQSC. 

“The HCM continues to serve as the definitive resource for assessing highway facilities in the U.S. and internationally,” she said. “In addition to the UF faculty and students who have contributed to its development so far, there are also several of our graduates now serving on the HCQSC and its subcommittees.” 

The Manual includes information on estimating capacity and level of service for transportation facilities, roadways, intersections, transit, pedestrians, and bicycles, to name just a few. The Manual is constantly updated by researchers to reflect the latest traffic analysis methods and technologies. 

UF’s contribution to the HCM has included an improved methodology for assessing two-lane highway capacity operational performance, new methodologies for evaluating interchange ramp terminals, new methodologies for evaluating corridors involving freeways and surface streets, and UF researchers have also contributed to understanding and measuring capacity and travel time reliability. The list of UF projects that have created new methodologies or revised existing methodologies, as well as those that have set new directions for HCM research are provided at the end of this document. 

There have been seven editions of the HCM. The last edition of the Manual was published in January 2022, and the transportation faculty at the University of Florida have played an integral role for this version as well.  

“The partnership between the UFTI and Committee has been exemplary, and the institute’s continuous involvement has helped the development of the HCM” Creasey said.  

To implement the methods in the HCM, practitioners most commonly use the Highway Capacity Software (HCS) package, which is managed by McTrans, a center housed at the UFTI. McTrans implements updates into the software and releases new versions as needed. McTrans works with HCM users and the HCQSC to monitor any updates and changes to the HCM and releases new versions of HCS as needed. HCS is used by 15,000 practitioners worldwide.  

UF Projects which have contributed to the HCM: 

STRIDE Project K2: Assessing and Addressing Deficiencies in the HCM Weaving Segment Analyses (2021)-   Proposing changes to freeway weaving methodology on HCM 6th edition and future research directions 

NCHRP 15-57: Highway Capacity Manual Methodologies for Corridors Involving Freeways and Surface Streets (2020) – Implemented as Chapter 38 of the HCM 7th edition  

NCHRP 17-65: Improved Analysis of Two-Lane Highway Capacity and Operational Performance (2018) – Implemented in the HCM 7th edition  

FHWA Highway Capacity Manual (HCM) Systems Analysis Methodology (2016) – Provided supplemental guidance for interchange analysis on HCM 6th edition and future research directions 

SHRP 2 Report S2-L08-RW-1: Incorporating Travel Time Reliability into the Highway Capacity Manual (2014). 

NCHRP 3-85:  Guidance for the Use of Alternative Traffic Analysis Tools in Highway Capacity Analysis, December 2009 

NCHRP 3-87: Proactive Ramp Management Under the Threat of Freeway-Flow Breakdown,  December 2009 

NCHRP 3-60A:  Validation and Enhancement of the Highway Capacity Manual’s Interchange Ramp Terminals Methodology (2009) 

New Calculation Method for Existing and Extended HCM Delay Estimation Procedures (2005), Transportation Research Board 85th Annual Meeting Capacity and Quality of Service of Interchange Ramp Terminals (2005, Transportation Research Record) 

Other references with UF researchers on the HCM: 

Courage, K. G., and J. Z.-Y. Luh. Computation of Signalized Intersection Service Volumes Using the 1985 Highway Capacity Manual. In Transportation Research Record 1194, Transportation Research Board, National Research Council, Washington, D.C., 1988, pp. 179–190. 

Courage, K. G., C. E. Wallace, and R. Alqsem. Modeling the Effect of Traffic Signal Progression on Delay. Transportation Research Record 1194, 1988 

Courage, K. G., S. Washburn, L. Elefteriadou, and D. Nam. Guidance for the Use of Alternative Traffic Analysis Tools in Highway Capacity Analyses. National Cooperative Highway Research Program Project 03-85 Final Report. University of Florida, Gainesville, 2010 

Elefteriadou, L., M. Armstrong, Y. Zheng and G. Riente. Highway Capacity Manual (HCM) Systems Analysis Methodology. Federal Highway Administration, Washington, D.C., 2016. 

Elefteriadou, L., H. Xu, and L. Xe. Travel Time Reliability Models. Florida Department of Transportation, Tallahassee, Aug. 2008 

Elefteriadou, L., A. Elias, C. Fang, C. Lu, L. Xie, and B. Martin. Validation and Enhancement of the Highway Capacity Manual’s Interchange Ramp Terminal Methodology. Final Report, National Cooperative Highway Research Program Project 3-60A. University of Florida, Gainesville, 2009. 

Harwood, D. W., D. J. Torbic, K. R. Richard, W. D. Glauz, and L. Elefteriadou. NCHRP Report 505: Review of Truck Characteristics as Factors in Roadway Design. Transportation Research Board of the National Academies, Washington, D.C., 2003 

Kittelson, W. K., K. G. Courage, M. D. Kyte, G. F. List, R. P. Roess, and W. M. Sampson. Highway Capacity Manual Applications Guidebook. Transportation Research Board of the National Academies, Washington, D.C., 2003. http://www.hcmguide.com. Accessed Sep. 4, 2020.  

Li, J., and S. S. Washburn. Improved Operational Performance Assessment for Two-Lane Highway Facilities. Journal of Transportation Engineering, Vol. 140, Issue 6, June 2014. https://doi.org/10.1061/(ASCE)TE.1943-5436.0000666 

Morriss, Jessica.  Identification of Preferred Performance Measures for the Assessment of Level of Service on Two-Lane Highways.  Masters Thesis, University of Florida.  Committee Chair: Scott S. Washburn.  December 2005. 

Ozkul, Seckin and Washburn, Scott S. Updated Commercial Truck Speed versus Distance-Grade Curves for the Highway Capacity Manual.  Transportation Research Record: Journal of the Transportation Research Board.  No. 2483, Transportation Research Board of the National Academies, Washington, D.C., 2015, pp. 91–101. DOI: 10.3141/2483-11 

Ozkul, Seckin, Washburn, Scott S., and McLeod, Douglas S. Revised Version of the Automobile Level-of-Service Methodology for Urban Streets in the Highway Capacity Manual 2010.  Transportation Research Record: Journal of the Transportation Research Board.  No. 2395, Transportation Research Board of the National Academies, Washington, D.C., 2013, pp. 66–72. DOI: 10.3141/2395-08 

Robinson, B. W., L. Rodegerdts, W. Scarbrough, W. Kittelson, R. Troutbeck, W. Brilon, L. Bondzio, K. Courage, M. Kyte, J. Mason, A. Flannery, E. Myers, J. Bunker, and G. Jacquemart. Roundabouts: An Informational Guide. Report FHWA-RD-00-067. Federal Highway Administration, U.S. Department of Transportation, Washington, D.C., June 2000. 

Sasahara, F., L. Elefteriadou, and S. Dong. Lane-by-Lane Analysis Framework for Conducting Highway Capacity Analyses at Freeway Segments. Transportation Research Record: Journal of the Transportation Research Board, Vol. 2673, Issue 8, 2019, pp. 523–535. 

Sasahara, F., L. Carvalho, T. Chowdhury, Z. Jerome, L. Elefteriadou, and A. Skabardonis. Predicting Lane-by-Lane Flows and Speeds for Freeway Segments. Transportation Research Record: Journal of the Transportation Research Board, Vol. 2674, Issue 9, 2020, pp. 1052–1068Washburn, S. S., and S. Ozkul. Heavy Vehicle Effects on Florida Freeways and Multilane Highways. FDOT Project BDK77 977-15. Florida Department of Transportation, Tallahassee, Oct. 2013. 

Washburn, Scott S., Al-Kaisy, Ahmed, Luttinen, Tapio, and Dowling, Richard, Watson, Donald, Jafari, Amirhossein, Bian, Zilin, and Elias, Aaron.  Improved Analysis of Two-Lane Highway Capacity and Operational Performance.  NCHRP Project 17-65.  Transportation Research Board.  March 2018.  670 pages.  DOI: 10.17226/25179 

Washburn, S., and B. Ko. Travel Time Reliability and Truck Level of Service on the Strategic Intermodal System. Florida Department of Transportation, Tallahassee, 2007 

Washburn, S. S., and D. S. Kirschner. Rural Freeway Level of Service Based on Traveler Perception. In Transportation Research Record: Journal of the Transportation Research Board, No. 1988, Transportation Research Board of the National Academies, Washington, D.C., 2006, pp. 31–37. DOI: 10.3141/1988-06 

Webster, N., and L. Elefteriadou. A Simulation Study of Truck Passenger Car Equivalents (PCE) on Basic Freeway Segments. Transportation Research Part B, Vol. 33, No. 5, 1999, pp. 323–336 

Zheng, Y., and L. Elefteriadou. A Model of Pedestrian Delay at Unsignalized Intersections in Urban Networks. Transportation Research Part B – Methodological. Vol. 100, 2017, pp. 138–155