Transportation Intelligence

Volume 3 Number 4

August 2005

Winter Maintenance

Structures

Pavements

Soils and Materials

Safety

Administration

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Safety
Pedestrian Safety Impacts of Curb Extensions: A Case Study
This report documents a case study evaluating motorist yielding behavior at a crosswalk in Albany, Oregon. In 2003 the City of Albany installed curb extensions, continental markings and advance stop bars at several uncontrolled intersections along the U.S. Highway 20 one-way couplet. (Oregon Department of Transportation Report SPR 304-321, July 2005, 34 p.)

Administration
Well Measured - Developing Indicators for Comprehensive and Sustainable Transport Planning
This paper provides guidance on the selection of indicators for comprehensive and sustainable transportation planning. It discusses the concept of sustainability and the role of indicators in planning, describes factors to consider when selecting indicators, identifies potential problems with conventional indicators, describes examples of indicators and indicator sets, and provides recommendations for selecting indicators for use in a particular situation. (Victoria Transport Policy Institute Paper, July 2005, 35 p.)

Structures
Concrete Bridge Deck Condition Assessment Guidelines
Although the substructures and superstructures of bridges in Utah are in relatively good structural condition, the bridge decks are experiencing observable deterioration due to the routine application of deicing salts and repeated freeze-thaw cycling. This manual describes condition assessment methods and threshold values that may be used to determine whether rehabilitation or replacement of a given bridge deck is more appropriate when the severity and extent of deterioration warrant deck improvement. (Utah Department of Transportation Report UT-05-01, November 2004, 15 p.)

Winter Maintenance

Toronto Salt Management Plan Improved Again
The City of Toronto recently made improvements to its Salt Management Plan that included new storage, new methods like pre-wetting, and new technologies. The aim was to reduce salt use and thereby lower costs and lessen the impact of salt on the environment. (Better Roads, April 2005, pp. 24-27)

Winter Highway Operations
NCHRP Synthesis 344: Winter Highway Operations examines changes that occurred between 1994 and 2004 to practices and strategies used to control the impacts of winter weather on the safe and efficient movement of traffic. (TRB NCHRP Synthesis 344, 2005, 76 p.)

Investigation of User Costs and Benefits of Winter Road Closures
This project explores the user costs and benefits of winter road closures. When conditions become unsafe due to winter weather, road closures should allow users to avoid crash costs and eliminate costs associated with rescuing stranded motorists. Therefore, the benefits of road closures are the avoided safety costs. The costs of road closures are the delays that are imposed on motorists and motor carriers who would have made the trip had the road not been closed. This project investigated the costs and benefits of road closures and found that evaluating the benefits and costs is not as simple as it appears. (Midwest Transportation Consortium Project 2003-1, June 2005, 73 p.)

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Structures

Risk Assessment and Update of Inspection Procedures for Culverts
A new culvert inspection rating system was developed by ODOT and described in their 2003 Culvert Inspection Manual. ORITE developed a proposed rating system and tested it and the ODOT system on 60 culverts in 8 of 12 ODOT Districts across the state. A risk assessment of the culverts was conducted based on the NCHRP Report 251 using an adjusted overall culvert rating. A number of innovative culvert rehabilitation techniques were discussed, including slip-lining, cured-in-place pipe, invert replacement using concrete or gunite, filling voids, and repairing sleeves for localized problems. (Ohio Department of Transportation Report FHWA/OH-2005/002, February 2005, 428 p.)

Effect of Crack Motion During Epoxy Crack Injection and Curing
One strategy to regain structural integrity of cracked reinforced concrete bridge deck girders is to inject the cracks with epoxy. Many bridge owners allow all traffic to use the bridge during injection and curing, while other bridge owners restrict traffic to produce a hold time in which cracks do not open and close. This research study used a laboratory set up to determine the effect of temperature and hold time on epoxy undergoing curing. The comparative measure was the tensile strength of the epoxy after curing. The results showed that traffic should be restricted to stop the crack motion during injection and until the epoxy sets. After the epoxy has set, crack motion while the epoxy undergoes full cure degrades the tensile strength of the epoxy, but not to levels that would affect the structural integrity of the beam. (Oregon Department of Transportation Report SPR 611, June 2005, 54 p.)

Covered Bridge Manual
This manual provides guidance to those involved in all aspects of the work, from initial inspection and evaluation, through the engineering of rehabilitation, to construction issues. Broadly speaking, this manual covers general terminology and historic development of covered bridges. The manual also addresses loads, structural analysis, connections, and design issues. The last six chapters contain discussions of evaluation, maintenance, strengthening, and preservation of existing covered bridges; historic considerations of existing structures, and provide a state-of-the-art guide on wood preservatives for covered bridges. Historic preservation requirements as they relate to the US Department of the Interior standards for these important and unusual structures also are provided. The appendices include an extensive series of case studies. (FHWA Report FHWA-HRT-04-098, April 2005, 341 p.) (Request this item from the TIS.)

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Pavements

Road Rehabilitation Energy Reduction Guide for Canadian Road Builders
Until recently, energy costs, although significant, have not been a major cost driver for the road building industry. As a result, the industry has typically done little monitoring of its energy use. In fact, the industry practice for factoring energy costs into a contract bid has traditionally been to assume a set price for fuels and to absorb any additional fuel costs brought about by a rise in fuel prices between the time a bid is accepted and the completion of the construction. In April 2004, the CCA Roadbuilders and Heavy Construction Council made energy reduction a priority for the road building industry.With funding from CIPEC, CCA contracted the Athena Sustainable Materials Institute to work with its members on a road rehabilitation energy-reduction guide for Canadian road builders. The recommendations in this guide are based in part on an energy use survey conducted by the Institute. (Natural Resources Canada with Canadian Construction Association, 2005, 30 p.)

Effects of Heavy Loading on Wisconsin's Concrete Pavements
This report consists of a research study that developed design guidelines for heavy truck loading in Wisconsin. The study was to address concerns expressed in a 2001 Report of Early Distress for a 6.5-mile stretch of USH 8 and an 8-mile stretch of USH 51 near Rhinelander, Wisconsin. A literature review was conducted to find all relevant information to rigid pavement design practices. In addition, concrete pavement design guides were solicited from U.S. states and Canadian provinces within solid frost regions, similar to Wisconsin. (Wisconsin Highway Research Program Report WHRP 05-06, May 2005, 74 p.)

Laboratory Accelerated Stripping Simulator for Hot Mix Asphalt
Moisture susceptibility of hot mix asphalt (HMA) pavements continues to be a major pavement distress. Past research has primarily focused on HMA stripping prevention through material component evaluation/testing and addition of preventative additives. Stripping is caused by traffic, water, and high in-place service temperatures. Today, agencies use various methods to evaluate HMA moisture susceptibility with varying degrees of success. The study objective was to evaluate a prototype stripping simulator’s ability to predict HMA moisture susceptibility.(FHWA/Mississippi Department of Transportation Report FHWA/MS-DOT-RD-04-167, January 2005, 157 p.)

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Soils and Materials

Qualitative Assessment of Aggregate for Presence of Clay
The presence of clay in aggregate has significant impact on the performance of concrete, asphalt mixes and granular bases. Two different test procedures are currently used in the industry to determine the presence of clay in aggregates. The Ontario Provincial Standard Specification (OPSS) uses a test method that was developed for clayey soils (the Atterberg limit tests). The Association of American State Highway and Transportation Officials (AASHTO) recommends the methylene blue adsorption method, which is a titration technique that is widely used in the oil industry to check the drilling fluid. The intent of this study is to investigate the effectiveness of the current OPSS standard and the test methods employed to determine the presence of clays in aggregates, and to recommend a test method that is effective, simple, inexpensive, and easy to perform. (Ministry of Transportation - Ontario Report MERO-016, April 2005, 51 p.)

Review of Stability Berm Alternatives for Environmentally Sensitive Areas
Stability berms are commonly constructed where roadway embankments cross soft or unstable ground conditions. Under certain circumstances, the construction of stability berms cause unfavorable environmental impacts, either directly or indirectly, through their effect on wetlands, endangered species habitat, stream channelization, longer culvert lengths, larger right-of-way purchases, and construction access limits. Due to an ever more restrictive regulatory environment, these impacts are problematic. The result is the loss of valuable natural resources to the public, lengthy permitting review processes for the department of transportation and permitting agencies, and the additional expenditures of time and money for all parties. The purpose of this project was to review existing stability berm alternatives for potential use in environmentally sensitive areas. The project also evaluates how stabilization technologies are made feasible, desirable, and cost-effective for transportation projects and determines which alternatives afford practical solutions for avoiding and minimizing impacts to environmentally sensitive areas. (Iowa Center for Transportation Research and Education Project 05-203, June 2005, 68 p.)

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Safety

Field Testing and Implementation of Dilemma Zone Protection and Signal Coordination at Closely-Spaced High-Speed Intersections
Historically, high speed signalized intersections have reported many crashes and have always posed a challenge to traffic engineers for enhancing safety at these intersections. The area close to the intersection, called the dilemma zone, poses a high accident potential for the driver in stopping safely during the yellow interval or in proceeding through the intersection before the beginning of red. The driver is in a potentially hazardous situation whereby, if he tries to cross the intersection at the onset of red interval, he may end up in an angle accident with the cross street traffic or if he accelerates through yellow, he may end up in a rear-end collision. The uncertain situation in a dilemma zone can potentially lead to rear-end or right angle collisions. (Ohio Department of Transportation Report FHWA/OH-2005/006, May 2005, 91 p.)

Pedestrian Crosswalk Safety: Evaluating In-Pavement, Flashing Warning Lights
Accidents involving pedestrians on crosswalks are a common cause of road fatalities. In-pavement flashing warning lights have been proposed as a means of increasing the conspicuity of a crosswalk when a pedestrian is using it. Evaluations in California and Washington have demonstrated the effectiveness of such in-pavement flashing warning lights on moderating drivers’ behavior when approaching a crosswalk. However, in-pavement flashing warning light systems are more expensive to install than striping, the conventional way of identifying crosswalks. This report describes work undertaken to determine the effect of an in-pavement flashing warning light system installed on a crosswalk on pedestrian safety, relative to striping. (University Transportation Research Center, March 2002, 49 p.)

Improved Grade Crossing Safety with In-Pavement Warning Lights
The focus of this project is the modification of a commercially available in-pavement warning signal that was evolved from one originally designed to indicate the presence of pedestrians in a crosswalk. We have proposed use of a similar device to provide warning to vehicles approaching a railroad grade crossing, and we have tested a variety of illumination patterns in order to provide an optimal implementation of such a warning device. Our laboratory tests demonstrate an improvement in visual response, as evidenced by a lowered reaction time, to a pattern that incorporates alternating groups of spatially-separated flashed LEDs in order to stimulate perception of movement. We have also completed preparations, including installation, for a future field test to study vehicle behavior in the presence of embedded warning lights incorporating this modified firing pattern. (California PATH Report UCB-ITS-PRR-2005-10, March 2005, 60 p.)

Effects on Road Safety of 30 Kilometer-Per-Hour Zone Signposting in Residential Districts
In Switzerland, reduced speed limits of 30 km/h are imposed mainly on local and collector streets in residential areas. This article discusses the effect of this speed limit on frequency and severity of accidents. (ITE Journal, June 2005,pp. 50-54)(Request this item from the TIS.)

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Administration

Transportation Performance Measures in Australia, Canada, Japan, and New Zealand
The purpose of this international scan was to investigate the use of performance measures in transportation planning and decision- making in selected countries. Performance measures can relate to many different aspects of and be applied at different levels of decision- making, so the scan panel represented a diverse set of interests and concerns for both national and State-level decision-making. (FHWA International Programs Report FHWA-PL-05-001, 2004, 108 p.)

Asset Management in Planning and Operations - A Peer Exchange
Asset Management in Planning and Operations--A Peer Exchange summarizes a September 7–8, 2004, peer exchange that focused on the expanding role of asset management in planning and operations as a comprehensive approach to managing agency resources and transportation systems. The peer exchange was designed to gather additional information about the state of the practice of asset management and to identify research needs and potential areas for innovation. (TRB Electronic Circular E-C076, June 2005, 66 p.)

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