TAC Transportation Intelligence

Structures
Findings of the international road tunnel fire detection research project
Fire detection systems are an essential element of fire protection for road tunnels. Fire detectors should provide early warning of a fire incident, identify its location and monitor fire development in tunnels. Their role can make the difference between a manageable fire and one that gets out of control. As such, fire detection systems play a crucial role in ensuring safe evacuation and firefighting operations. (National Research Council of Canada report NRCC-50542, March 2008, 12 p.)

Pavements
Estimation of the relationships of road deterioration to traffic and weather in Canada
The main objective of this project is to provide estimates on the nature of the contribution of traffic and climate to wear of pavements. The project involves a detailed review of existing information available in the literature. It also involves a review of existing design practices in Canada and of available data to support the assessment of pavement deterioration and validation and calibration of performance models. The project also involves running a limited number of performance simulations in order to assess prelimianry estimates of rates of wear to be attributed to traffic and climate. (Transport Canada Report T8080-04-0242, May 2005, 244 p.)

Safety
Cross Median Crashes: Identification and Countermeasures
The goals of this project were to first review the state-of-art with regard to identifying highway sections where median barriers would be most effective in preventing median-crossing crashes (MCC), and if necessary, develop remedies for any identified deficiencies. A statistical technique was developed for estimating the frequency and rate of MCCs on each of a set of highway sections. (Minnesota Department of Transportation Report MN/RC 2008-17, June 2008, 63 p.)

Combining Climate, Crash, and Highway Data for Improved Ranking of Speed and Winter-Weather Related Crash Locations in Oregon
In recent years, the techniques for screening transportation networks to identify high crash locations have become more sophisticated with significant data requirements. This paper presents the results of an empirical analysis of screening and ranking for weather related crashes on rural 1.6 km (1 mi) highway sections of Oregon highways. The analysis includes data generated with the extensive use of spatial techniques and incorporates climate data to enhance environmental considerations. The paper compares the results of five ranking methods: Critical rate (by functional class), critical rate (by functional class and climate zone), potential for crash reduction, expected frequency (adjusted by empirical-bayes), and frequency. (Journal of Transportation Engineering, July 2008, pp. 287-296)(To obtain a copy of this item, please contact the TIS.)

Administration

Estimation of Noise Costs due to Road, Rail and Air Transportation in Canada
This report describes methods of calculating total and marginal costs for noise externality costs associated with air, rail, and road. It reports total annual noise costs calculated for Canada and for each province. The report provides description of how to calculate measures of total and marginal noise costs for six (6) transportation activities; air, rail, road (automobile, truck, Intercity bus, public transit bus) but provides actual measures for road, rail and air; the road mode could not be segmented due to a lack of data. (Noise and the Full Cost Investigation in Canada: Final Report, March 2007, 35 p.)

Management & Operations in the Metropolitan Transportation Plan: A Guidebook for Creating an Objectives-Driven, Performance-Based Approach
This guidebook is designed to provide a basis on which to integrate transportation system management and operations (M&O) into the metropolitan transportation planning process and to assist MPOs in meeting Federal requirements under SAFETEA-LU calling for M&O strategies to be incorporated into the metropolitan transportation plan (MTP). It highlights effective practices that result in an MTP with a more optimal mix of infrastructure and operational strategies, founded on the inclusion of measurable, performance-based regional operations objectives. (FHWA Interim Report FHWA-HOP-08-007, November 2007, 66 p.)

Valuing Transit Service Quality Improvements
This article investigates the value transit travelers place on qualitative factors, such as comfort and convenience, and practical ways to incorporate these factors into transport planning and project evaluation. Conventional evaluation practices generally assign the same time value regardless of travel conditions, and so undervalue comfort and convenience impacts. More comprehensive analysis of transit service quality tends to expand the range of potential transit improvement options, and justify more investments in transit service quality improvements. This article examines the value passengers place on transit service quality, summarizes research on travel time valuation, explores how transit service quality factors affect travel time values and transit ridership, and discusses implications of this analysis. (Journal of Public Transportation vol. 11 no. 2, 2008, 21 p.)

Web-Based Guide to Transportation Benefit-Cost Analysis
This web site helps users, step by step, through the process of determining if benefit-cost analysis (BCA) is an appropriate approach to an investment decision for a particular transportation project and then, if so, of properly conducting the analysis. Although not intended as an instructional aid per se, the site provides elementary guidance on setting up and conducting a BCA, explaining concepts and the basics of appropriate methodologies. It also lets users drill down to detailed technical descriptions of methodologies, analysis tools, and illustrative case studies. The site was developed in order to encourage increased use and proper application of BCA in transportation investment decisions for which this approach is appropriate. Check out: http://www.dot.ca.gov/hq/tpp/offices/ote/Benefit_Cost/. (Journal of Transportation Engineering, July 2008, pp. 282-286)(To obtain a copy of this item, please contact the TIS.)

The development of gravel deterioration models for adoption in a New Zealand gravel road management system
Part A of this report focuses solely on the improvement of unsealed road performance through construction and maintenance processes. The data from the past five years was analysed and the results are presented in Part B of this report. (Land Transport New Zealand Research Report 348, June 2008, 98 p.)

Pavements

Refining the Simple Performance Tester for Use in Routine Practice
This report presents the findings of a research project to develop a practical, economical simple performance tester (SPT) for use in routine hot-mix asphalt (HMA) mix design and in the characterization of HMA materials for pavement structural design with the Mechanistic- Empirical Pavement Design Guide. In the work reported here, the effectiveness and efficiency of the SPT were substantially improved for its use in routine, day-to-day pavement structural design with the MEPDG. Thus, the report will be of particular interest to materials and pavement structural design engineers in state highway agencies, as well as to materials suppliers. (TRB's National Cooperative Highway Research Program Report 614, 2008, 153 p.)

Effects of Supplementary Cementing Materials on the Setting Time and Early Strength of Concrete
The substitution of a portion of cement in concrete with supplementary cementing materials (SCM) frequently results in delayed setting and low early strength. When SCM-containing concrete is placed during cold weather and/or contains certain chemical admixtures, these problems can intensify and can seriously impact the performance of a pavement. This project investigated the setting time, early strength gain, maturity, bleeding, and plastic shrinkage cracking of several concrete pavement mixtures containing SCM under different temperature conditions (mimicking summer, spring, and winter weather). The data were used to develop guidelines for identifying slow-setting mixtures and preventing their use in pavements. (Texas Department of Transportation Report FHWA/TX-08/0-5550-1, February 2007, Rev. May 2008, 81 p.)

Evaluation of Using Higher Percentages of Recycled Asphalt Pavement in Asphalt Mixes in Virginia
In 2007, the Virginia Department of Transportation (VDOT) decided to allow higher percentages of recycled asphalt pavement (RAP), i.e., more than 20 percent, in hot-mix asphalt with no change in binder grade. Because of this increase, one section of the contract provisions in certain plant-mix overlay schedules around the state had to be rewritten to raise the limit on the proportion of recycled material to 30 percent from the customary 20 percent. The purpose of this study was to estimate the effect of increased RAP percentages on performance and relative mixture cost on specific VDOT paving projects in 2007. (Virginia Transportation Research Council Report VTRC 08-R22, June 2008, 29 p.)

Evaluation of Long-Term Pavement Performance and Noise Characteristics of Open-Graded Friction Courses - Project 2
This experimental project is being conducted as a part of WSDOT’s effort to produce pavements that reduce the noise generated at the tire/pavement interface. Experimental sections of open-graded friction courses were built using asphalt rubber and SBS modified binders. A section of conventional Class ½ inch hot mix asphalt (HMA) serves as the control section for the two experimental sections. (Washington State Department of Transportation Report WA-RD 691.1, March 2008, 62 p.)

Network-Level Pavement Evaluation of Virginia's Interstate System Using the Falling Weight Deflectometer
The Virginia Department of Transportation (VDOT) currently uses the results of automated surface distress surveys to assist in developing pavement maintenance strategies for its interstate and primary roadways. These video-based surface distress data consist of quantities of distress that is visible in the pavement surface; however, no information regarding the actual structural capacity of the pavement system on a network level is currently available. This study describes the processes and presents the results of a network-level survey conducted on Virginia’s interstate system using the falling weight deflectometer (FWD). (Virginia Transportation Research Council Report VTRC 08-R18, June 2008, 123p.)

Traffic Control

Interim Guidebook on Congestion Management Process (CMP)
The Congestion Management Process (CMP), which has evolved from what was previously known as the Congestion Management System (CMS), is a systematic approach, collaboratively developed and implemented throughout a metropolitan region, that provides for the safe and effective management and operation of new and existing transportation facilities through the use of demand reduction and operational management strategies. This guidebook provides information on how to create an objectives-driven, performance-based congestion management process. While the focus of this guidebook is on the CMP, the principles of objectives-driven, performance-based planning can also be applied to other aspects of regional concern (safety, economic development, environment, etc.). (FHWA Interim Report FHWA-HOP-08-008, February 2008, 62 p.)

Effectiveness of incident management on network reliability
This report summarises preliminary research undertaken in New Zealand during 2006–07 to investigate the ability of intelligent transport system (ITS) treatments to detect and respond to serious traffic incidents, and to determine the most appropriate traffic management strategies (in terms of overall network reliability) to apply when such incidents are detected. The study involved a literature review of techniques and software/systems currently used to manage traffic congestion and respond to incidents, and an exploratory microsimulation study modelling incident detection and response in an urban network. (Transport New Zealand Research Report 346, June 2008, 61 p.)

Signalized Intersection Analysis and Design: Implications of Day-to-Day Variability in Peak-Hour Volumes on Delay
This paper presents findings of a study that quantifies the impact of day-to-day variability of intersection peak-hour approach volumes on intersection delay and demonstrates that this impact is not insignificant and therefore should not be ignored. Finally, the study explores the number of days for which intersection approach volumes should be counted in order to establish intersection delay within a desired level of confidence. (Journal of Transportation Engineering, July 2008, pp.307-318)(To obtain a copy of this item, please contact the TIS.)

Régulation multimodale du trafic routier et des transports en commun de surface: Une classification des méthodes (Multimodal control of road traffic and public transport: A classification of methods)
In this paper, the different means and methods for the control of bus and cars are described. The objective is not to describe every existing system, but to propose a typology of methods used inside these systems and illustrate it by the example of one system in each category. (Recherche Transports Sécurité, janvier-mars 2008, pp. 53-72)(To obtain a copy of this item, please contact the TIS.)

Transportation Intelligence

Volume 6 Number 4

August 2008

Structures

Administration

Pavements

Traffic Control

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Structures

Administration

Pavements

Traffic Control