This past month several representatives of the University of Florida Transportation Institute traveled to Berlin, Germany for the International Symposium on Enhancing Highway Performance (ISEHP). This joint international symposium was organized by two Transportation Research Board (TRB) committees (Highway Capacity and Quality of Service – AHB40 and Freeway Operations -AHB20) and the German Road and Transportation Research Association (FGSV). The conference provided a common platform for decision makers, managers, traffic engineers, practitioners, and researchers to share their international experience in analyses of highway capacity, quality of service, and of freeway and tollway operations.
UFTI Affiliate Dr. Scott Washburn co-chaired and presented an overview of the NCHRP Project 17-65 at the Rural Highways Workshop on Operational Analysis in Rural Highways: Two-Lane Highways, 2+1 Highways and Traffic Micro-simulation Tools. You can learn more about the workshop here.
UFTI Director Dr. Lily Elefteriadou presented “An Overview of the US HCM Update” during the Country Reports, Part I Technical Session.  She also chaired the second part of that technical session, co-chaired the Joint Committee Meeting and participated in the AHB40 Highway Capacity and Quality of Service Committee Meeting, of which she is the past chair. Students Yinan Zheng and Gustavo Riente de Andrade also presented research papers at the symposium.  The abstracts of their presentations are provided below.

An Overview of the US Highway Capacity Manual (HCM) Update
This presentation provided an overview of the HCM 6th Edition in order to familiarize transportation practitioners and researchers with the extensive set of analysis tools the publication provides. It first discussed the scope of HCM analyses, and then provided an overview of some of the most relevant and significant applications that have been added to this edition of the HCM. The presentation also summarized the process typically followed in developing and updating this document, along with information for getting involved with the US Highway Capacity and Quality of Service Committee.

Pedestrian Traffic Operations in Urban Networks
Yinan Zheng, Lily Elefteriadou, Thomas Chase, Bastian Schroeder, Virginia Sisiopiku
The pedestrian mode is an important component of urban networks, and greatly affects the performance of the sidewalks and crosswalks, as well as the entire network traffic operations by interacting with other traffic modes (automobile, bicycle, transit). There have been many studies concerning different aspects of pedestrian behaviors, such as pedestrian walking speed, pedestrian delay, gap acceptance, signal compliance, route choice, etc. The Highway Capacity Manual (HCM) included the pedestrian mode in the HCM 1994 (update to the HCM 1985) and the HCM 2010 provided several basic technical methodologies for evaluating the pedestrian level of service (LOS) of different urban street facilities. However, it does not fully cover the pedestrian operation in a great detail and it is missing some important findings in recent studies. The objective of this paper is to provide an overview of pedestrian operations in urban networks, to identify the important aspects of pedestrian operation analysis and to provide recommendations for pedestrian facilities in the HCM on the basis of a summary of available U.S. and international literature. The following topics were discussed: pedestrian movement models, pedestrian delay estimation, pedestrian-vehicle interactions, and pedestrian travel time estimation.

A Model for Estimating Free-Flow Speed on Brazilian Expressways
Gustavo Riente de Andrade, Cira Souza Pitombo, André Luiz Cunha and José Reynaldo Setti
Free flow speed (FFS) is defined in the HCM as the “average speed of vehicles on a given segment, measured under low-volume conditions, when drivers are free to travel at their desired speed and are not constrained by the presence of other vehicles or downstream traffic control devices”. FFS is a very important parameter for the estimation of LOS and capacity for uninterrupted highways facilities. Ideally, FFS is determined using field measurements, but the HCM 2010 provides models for its estimation, when field data is not available. Such models must be recalibrated for local conditions when the HCM 2010 is adapted for use in countries outside North America. In this paper, Multivariate Analysis (MVA) techniques are used to investigate which infrastructure characteristics are related to FFS on Brazilian expressway facility segments, in order to provide a framework for the development of models to replace those used in HCM 2010 to estimate FFS. This study used a database with a large number of speed-flow observations obtained at 36 sites on Brazilian expressways (freeways and divided multilane highways), along with information on seven variables describing segment characteristics such as: expressway type; roadside environment; number of lanes; rise and fall; bendiness; access point density; and posted speed limit for passenger cars. Principal Component Analysis (PCA) was used to select the variables to be included in the proposed model. The results of the PCA indicated that three components are responsible for most of the variance on observed FFS: (1) posted speed; (2) the combined effects of road class, number of lanes and density of access points; and (3) the interaction of geometric design and roadside environment. Stepwise linear regression was used to fit a FFS model from these three components. This model was mathematically manipulated to provide a FFS that is structurally similar to the one used by HCM 2010 but in fact accounts for the interactions among variables. The proposed model can replace the HCM 2010 model and does not require the user to choose an initial value for the base FFS.