Transportation Intelligence

Volume 8 Number 4

August 2010
Pavements
Administration
Safety
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Urban
From Buses to BRT: Case Studies of Incremental BRT Projects in North America
Bus Rapid Transit (BRT) uses different combinations of techniques to improve service, such as bus-only lanes and roads, pre-boarding fare collection, transit priority at traffic signals, stylish vehicles with extra doors, bus stops that are more like light rail stations, and high frequency service. This study examines five approaches to BRT systems as implemented by public transit agencies in California, Oregon, and Ontario. (Mineta Transportation Institute report 09-13, June 2010, 110p.)

Administration
WIM Data Analyst's Manual
This manual provides information and recommended procedures to be utilized by an agency’s Weigh-in-Motion (WIM) Office Data Analyst to perform validation and quality control (QC) checks of WIM traffic data. This manual focuses on data generated by WIM systems that have the capability to produce high quality data. This manual has been developed to ensure that high quality WIM data is collected and used to produce reliable and representative load spectra for input into the Mechanistic-Empirical Pavement Design Guide (M-E PDG) software resulting in reliable and predictable pavement designs. (US Federal Highway Administration report FHWA-IF-10-018, June 2010, 183p.)
Research
Canadian Surface Transportation Research Survey
The Transportation Association of Canada (TAC) is conducting its annual inventory of research projects in surface transportation in Canada. Your contribution to this survey is particularly important since the data serves to provide a centralized information source for surface transportation research in Canada. The records in the database help us to monitor Canadian research activity, define the current state of the art, and identify experts in the field. Your input is gladly accepted at any time of the year. Inform us about new research by completing the R&D survey form or by forwarding your organization’s already published descriptions.

Pavements

Failure of Surface Courses Beneath Pavement Markings
Pavement markings can contribute to the deterioration of surface courses and in some cases it was found that the markings are the main source of distress. The reasons for such damage are outside the scope of this work but it was speculated that water vapor trapped under the pavement marking can lead to moisture damage and raveling in this high voids mixtures. Careful selection of the right treatment for the right condition along with proper controls during production, placement, and compaction of surface mixtures is still needed to obtain longer lasting pavement surfaces. (Utah Department of Transportation report UT-10.05, March 2010, 60p.)

Evaluation of Hot In-Place Recycle
This report documents the construction of hot in-place recycled (HIPR) pavement on SR 542. HIPR is a process by which rehabilitation of the existing HMA pavement occurs on site in one operation. HIPR project selection, mix design, construction and testing are described. The HIPR process successfully rehabilitated the pavement on SR 542 while using less new material than a traditional HMA mill and fill. HIPR was found to reduce initial project cost and traffic disruptions were less than HMA paving. This project will be evaluated for five years at which time a final report documenting the HIPR performance will be produced. (Washington State Department of Transportation Report WA-RD 738.1, June 2010, 78p.)

Environmentally Friendly Pavements - Final Report
This final report presents the main results, advice and recommendations from the research and development program Environmentally Friendly Pavements run by the Norwegian Public Roads Administration (NPRA) in the period 2004-2009. The main focus of the project has been to optimise the environmental properties of road surfaces with respect to low road tyre noise and road dust emissions. The project has shown that: The tested environmentally friendly pavements give an initial noise reduction of 3-9 dB(A) compared to the reference level (SMA11 older than one year). (Norwegian Public Roads Administration Report 2578, 18 December 2009, 79p.)

Development of Recommendations for Compaction Temperatures in the Field to Achieve Density and Limit as-built Permeability of HMA in Wisconsin
The objectives of this study were to (1) evaluate the effect of compaction effort and temperature on densification of HMA in the field and in the lab, (2) quantify the effects of Warm Mix additives on the compaction, and (3) create a dataset capable of determining the effect of as-built density and permeability on asphalt pavement performance. Field testing and loose-mix sampling occurred on 30 unique layers of HMA during the 2007 paving season, and a single Warm Mix project during the 2008 paving season. (Wisconsin Highway Research Program report 08-08, March 2009, 147p.)

Monitoring and Evaluation of Fly Ash Stabilized Subgrade Constructed by Wisconsin DOT
This report describes the monitoring and evaluation of a field site where Class C fly ash was used to stabilize the subgrade during construction of a rigid pavement in a portion of USH 12 near Fort Atkinson, Wisconsin. Additionally, information from a second similar project (STH 32 near Port Washington, WI) that was monitored only during construction and a third project (STH 60 near Lodi, WI) that was monitored for 8 years is reported. (Wisconsin Department of Transportation report 0092-04-10, 30 June 2010, 125p.)

Analysis of High Performance Concrete Pavement Sections Along I-90 Near Tomah, Wisconsin
This report presents the analysis of the High Performance Concrete (HPC) pavement sections constructed along the eastbound lanes of Interstate 90 near Tomah, Wisconsin. The test sections are the first specific HPC pavements designed and built in the State of Wisconsin and represent the current trends in building highway pavements with significantly longer service lives. Deflection data obtained with the WisDOT Falling Weight Deflectometer (FWD) was used to characterize the pavement materials within each section and to provide inputs for detailed mechanistic-empirical pavement analyses. The Mechanistic Empirical Pavement Design Guide (MEPDG) software was used to provide 60-year predictions of pavement performance within each test section. (Wisconsin Department of Transportation report FEP 02-09, June 2010, 45p.)

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Structures

Inhibiting Chloride-Induced Corrosion in Concrete Bridges
The use of de-icing salts can significantly reduce the service life of concrete transportation structures by causing corrosion of the reinforcing steel. This Update provides guidance on controlling corrosion, drawing on a ten-year study to assess the performance of eight commercial corrosion-inhibiting systems on a concrete highway bridge. (National Research Council Canada Institute for Research in Construction update 73, June 2010, 4p.)

Mitigation Strategies for Early-Age Shrinkage Cracking in Bridge Decks
Early-age shrinkage cracking has been observed in many concrete bridge decks in Washington State and elsewhere around the U.S. The cracking increases the effects of freeze-thaw damage, spalling, and corrosion of steel reinforcement, thus resulting in premature deterioration and structural deficiency of the bridges. In this study, the main causes of the early-age cracking in the decks are identified, and concrete mix designs as a strategy to prevent or minimize the shrinkage cracking are evaluated. (Washington State Department of Transportation Report WA-RD 747.1, April 2010, 91p.)

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Administration

Practical Methods for Analyzing Pedestrian and Bicycle Use of a Transportation Facility
The objective of the project is to analyze existing technologies used for the process of generating counts of bicycles and pedestrians in transportation facilities such as walk and bicycle bridges, urban bicycle routes, bicycle trails etc. The advantages and disadvantages of each existing technology which is being applied to counting has been analyzed and some commercially available products were listed. A technical description of different methods that were considered for vision based object recognition is also mentioned along with the reasons as to why such methods were overlooked for our problem. Support Vector Machines were used for classification based on a vocabulary of features built using interest point detectors. Upon detailed analysis the reasons for false counts and undercounting in some cases have been identified and current work concerns dealing with these issues. (Minnesota Department of Transportation report MN/RC 2010-06, February 2010, 41p.)

Freight Performance Measures: Approach Analysis
This report reviews the existing state of the art and also the state of the practice of freight performance measurement. Most performance measures at the state level have aimed at evaluating highway or transit infrastructure performance with an emphasis on passenger transportation. Freight performance measurement ultimately requires evaluation of performance of the entire freight transportation system, which includes highways, waterways, rail, air, and modal connections. (Oregon Department of Transportation Report FHWA-OR-RD-10-18, May 2010, 135p.)

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Safety

Summary Report: Evaluation of Lane Reduction "Road Diet" Measures and Their Effects on Crashes and Injuries
This Highway Safety Information System (HSIS) summary replaces an earlier one, Evaluation of Lane Reduction “Road Diet” Measures and Their Effects on Crashes and Injuries (FHWA-HRT-04-082), describing an evaluation of “road diet” treatments in Washington and California cities. This summary reexamines those data using more advanced study techniques and adds an analysis of road diet sites in smaller urban communities in Iowa. (US Federal Highway Administration summary report FHWA-HRT-10-053, 2010, 4p.)

Use of Traffic Channelization Devices at Highway-Rail Grade Crossings
The installation of traffic channelization devices at highway rail grade crossings has proven to be a cost-effective means of improving safety. The traffic channelization devices provide a proven safety benefit without the same hindrances to mobility that occur with crossing closure or the costs associated with four-quadrant gate systems. Median barriers/traffic channelization devices that meet the criteria within the Final Rule on the Use of Locomotive Horns at Highway-Rail Grade Crossings are approved supplemental safety measures for the establishment of a quiet zone. Implementing median barriers at a highway-rail grade with active warning crossing devices can reduce the risk of a collision at that crossing. (US Federal Railroad Administration report RR 10-03, June 2010, 4p.)

The relationship between road safety and congestion on motorways: A literature review of potential effects
This literature review investigates the relationship between congestion and safety at road sections of the main road network (mainly motorways) and specifically looks at unstable and congested traffic conditions. (SWOV Netherlands report R2010-12, 2010, 30p.)

Application of a Rural Safety Policy Improvement Index (RSPII) Framework
This research project was organized to investigate the feasibility and potential implementation of a rural safety policy improvement index (RSPII). An RSPII would be used to quantitatively estimate, state-by-state, the potential rural roadway safety impacts due to the enactment of and/or change to transportation safety policies or legislation. The activities completed to determine the feasibility of an RSPII were documented in the Phase I report of this project . It was concluded that the application of the RSPII was possible, but that improvements to the applicable research would result in updates to the process. This Phase II project report documents the application of the RSPII framework to six “proven” legislatively-based safety improvement measures (LSIMs). Challenges to the implementation of the RSPII framework and the rural application of LSIMs considered will also generally be discussed. In addition, conclusions and recommendations related to the application and improvement of the process and results described in this document are also provided. (University of Minnesota Center for Excellence in Rural Safety report CTS 10-07, May 2010, 67p.)

Safety and Operational Performance Evaluation of Two-Lane Exit Ramps with Optional Lane on Florida’s Freeways
This project mainly focuses on exit ramp performance analysis of safety and operations. In addition, issues of advance guide sign for exit ramp are also mentioned. Safety analysis includes the following two parts: to evaluate the impacts of different exit ramp types on safety performance for freeway diverge areas; and to identify the different factors contributing to the crashes happening on the exit ramp sections. Operational analysis determines different ramp effects, and guidance for selecting optimal exit ramp type. For advance guide sign, placement distance models are presented respectively for the three different installation methods: ground sign installation, overhead sign installation, and median sign installation. (Florida Department of Transportation report, November 2009, 192p.)

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Environment

Transportation's Role in Reducing U.S. Greenhouse Gas Emissions
This study evaluates potentially viable strategies to reduce transportation greenhouse gas (GHG) emissions. The study was mandated by the Energy Independence and Security Act (P.L. 110-140, December 2007). The Act directed the U.S. Department of Transportation (DOT), in coordination with the U.S. Environmental Protection Agency (EPA) and consultation with the U.S. Global Change Research Program (USGCRP), to conduct a study of the impact of the Nation’s transportation system on climate change and strategies to mitigate the effects of climate change by reducing GHG emissions from transportation. This study also examines the potential impact of these strategies on air quality, petroleum savings, transportation goals, costs, and other factors. (US Department of Transportation Report to Congress, April 2010, 605p.)

Salt SMART: Environmental damages caused by road salt - a literature review
The literature review focus on environmental damages on surface water (flora and fauna), ground water, terrestrial plants and soil caused by using deicing chemicals in winter road maintenance . An evaluation of the most actual alternatives to sodium chloride is given. An overview of how to handle salt storm water from roads are also given. (Norwegian Public Roads Administration Report 2587, 12 April 2010, 114p.)

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