A közlekedésépítési szakterület mérnöki és tudományos folyóirata. ISSN: 2064-0919
8. évfolyam
2020 december
14
Bejegyzés

# Nemzetközi szemle: Március

Burkolat állapotfelvételi és tervezési stratégiák fejlesztése nem államközi utakra

Development of Pavement Design and Investigation Strategies for Non-Interstate Routes

Szerző(k): N. Huynh, R. Mullen, S. Gassman, P. Ziehl, F. Ahmed

University of South Carolina USA

Terjedelem: 61 oldal

Kivonat:

This project investigated the state-of-the-practice on conducting field investigation for rehabilitation of non-interstate routes and whether field investigation is cost effective for the SCDOT. An online survey was conducted to determine the state-of-the-practice on pavement rehabilitation for non-interstate routes. A total of 29 responses were received from 21 state DOTs and eight state agencies. All of the respondents (100%) indicated that they perform field investigation before rehabilitation design. Some state DOTs perform a preliminary survey of the pavement condition and then perform field investigation, if needed. Other state DOTs use the same field investigation procedure for rehabilitation as new construction and some perform the field investigation regardless of the pavement functional condition. The top three methods being used to perform field investigation are: coring (93.1%), falling-weight deflectometer measurements (89.7%), and mobile scanning (55.2%). When cores are taken, the majority of the respondents (85.2%) indicated that they use them to measure both pavement thickness and distress. Lastly, the majority of the respondents (93.1%) indicated that they also investigate pavement distresses during rehabilitation design. To determine whether field investigation is cost-effective, the life-cycle costs and equivalent uniform annual costs of two different designs, one with field investigation and one without field investigation, were compared. The design with field investigation represents the design the SCDOT would use in the future if the SCDOT required field investigation to guide rehabilitation design for non-interstate routes. The design without field investigation represents the current design being used by SCDOT district engineers. The life-cycle cost analysis indicated that when the design with investigation is used instead of the design without investigation, the cost difference to maintain one lane-mile of pavement in good functional condition is -$27,030, in fair functional condition is -$12,220, and in poor functional condition is -\$37,348 over the 50-year analysis period; the negative cost difference indicates that it is a savings to the SCDOT.

These findings indicate that field investigation is generally cost-effective. Therefore, it is recommended that the SCDOT consider performing field investigation on pavements that are in fair and poor conditions. The investigation procedure for good pavements will likely be modified by on-going efforts from the traffic-speed deflectometer (TSD) pooled fund study and SPR 748.

Nagyvárosi területek hatékony közösségi közlekedésének jellemzői: európai, kanadai és ausztráliai esettanulmányok összehasonlítása

Characteristics of Effective Metropolitan Areawide Public Transit: A Comparison of European, Canadian, and Australian Case Studies

Szerző(k): M. DeRobertis, C.E. Ferrell, R.W. Lee, J.M. Eells

Mineta Transportation Institute San José State University USA

Terjedelem: 164 oldal

Kivonat:

This research project investigates the replicable characteristics, policies, and practices of successful metropolitan areawide public transportation networks that contribute to high usage and make transit an effective competitor to the private motor vehicle. The research method involves the qualitative and quantitative analysis of ten international (non-U.S.) case studies. The principal methods employed were web-based research and data collection, as well as telephone interviews with transit agency staff or regional planners as needed. The case studies were limited to developed western countries with similar metropolitan conditions to those in the United States. This research focuses on key characteristics of highly effective regional transit systems from the perspective of the metropolitan area, not the individual transit operators. These characteristics fall within three broad categories: the setting of the metropolitan area; the customer-apparent transit service features; and the behind-the-scenes or institutional characteristics. Key findings are: all ten case studies have a metropolitan areawide regional transit coordinator (RTC); RTCs yield benefits in terms of ridership and operating efficiencies that are discernable from the effects of high transit funding and subsidies; all case studies had some degree of fare integration, and most had complete regionwide fare integration; and transit service was frequent, abundant, and affordable in all cases. The features of excellent regionwide transit systems that have been identified in this research can be applied to U.S. metropolitan areas with multiple players, yielding effective, efficient, and high mode share public transit at the regional level. The research can help U.S. policy makers and planners begin to improve the appropriate aspects of their own regional transit systems, including by improving coordination and organizational structures.

Polimerrel modifikált kötőanyagú kísérleti építések vizsgálata és a kötőanyagok öregedési tulajdonságai

Inspections of Polymer Modified Binder Trial Sites and Ageing Properties of Binders

Szerző(k): S. Patrick, Y. Choi

letölthető ingyenes regisztrációval

Terjedelem: 105 oldal

Kivonat:

This report presents the findings of site inspections and binder ageing performance studies associated with two Austroads sprayed seal trial sites constructed near Coober Pedy, South Australia and Cooma, New South Wales. These trials were established to evaluate the relative performance of various grades of polymer modified binders (PMBs). After eight years of life, all trial sections of the Coober Pedy site were showing similar, satisfactory performance. Further monitoring of the Coober Pedy site is required so that variations in the performance of the different binders can be observed. The Cooma site showed signs of severe distress in several sections after six years of life, which led to resealing of the entire site. Changes in the surface texture depth of the seals at Coober Pedy and Cooma during service were investigated. This information was used to validate a new seal voids parameter. Various rheological and chemical tests were conducted on the trial binders. All binders showed complex property changes on ageing. More complex rheological tests (e.g. repeated loading tests) appear to be needed to develop a durability performance test for PMBs in the Austroads PMB specification (ATS3110).

Lézer alapú közúti behajlásmérő rendszer fejlesztése és kalibrálása

Development and Calibration of a Laser-based Highway Deflection Measuring System

Szerző(k): J. B. Hernandez, V. Suyash, C. Claudel, J.A. Prozzi

The University of Texas at Austin USA

Terjedelem: 111 oldal

Kivonat:

Despite recent developments, the measurement of actual pavement surface deflections under the axles of a moving truck at a network level remains a challenge in pavement engineering. Several pieces of equipment have been developed in the past decade but they fail to accurately measure actual deflection. Most of them measure indicators of deflection or deflection averages over a given distance. Pavement engineers recognize the usefulness of pavement deflection data to evaluating and monitoring pavement response and performance, assessing pavement structural conditions, and serving as an input for rehabilitation design. Network-level studies of pavement deflections are possible but have major limitations such as the lack of accurate measurements (actual deflection is not measured at any point), the inherent complexity, and safety concerns. Some accurate devices are available but they work at very low speed, posing safety concerns. The purpose of this project is to develop a laser-based highway deflection measuring system for network-level studies that continuously moves along the pavement at speeds of at least 10 mph.

Közúti Kapacitási Kézikönyv módszertan gyorsforgalmi és városi utakat tartalmazó folyosók számára

Highway Capacity Manual Methodologies for Corridors Involving Freeways and Surface Streets

Szerző(k): University of Florida Transportation Institute, Cambridge Systematics, Alex Skabardonis

Consultant, USA

Terjedelem: 390 oldal

Kivonat:

The procedures detailed in the 6th Edition of the Highway Capacity Manual (HCM) estimate capacity and several operational measures, including those determining Level of Service (LOS), for freeway facilities as well as surface streets. However, the HCM lacks a methodology for evaluating the operational performance of networks involving freeway-urban street interactions. The current HCM methods focus on operational analysis of individual segments or sections, which may not correspond to the traveler’s experience of an entire trip which traverses multiple different types of facilities. These methods do not consider cases in which spillback occurs from one type of facility to another, or across an entire origin-destination route, which is necessary for evaluation of network performance. The objective of this research project is to develop materials for the HCM in order to modify the freeway analysis methods and the urban street methods so that the effects of operations from one facility to the other can be evaluated. This report summarizes the entire research effort and provides the proposed new HCM Chapter (Chapter 38) in Appendix A- Chapter 38 – System Analysis. The new methods produced can be used to evaluate operations along networks that include both freeways and urban streets. The methods can also evaluate the impact of spillback into freeways and into urban streets from downstream facilities.

Tervezési eljárások fejlesztése alacsony kötőanyag tartalmú cementes anyagok számára hajlékony burkolatokban

Development of Design Procedures for Lightly Bound Cemented Materials in Flexible Pavements

Szerző(k): J. Grenfell, G. Jameson, P. Hunt

letölthető ingyenes regisztrációval

Terjedelem: 204 oldal

Kivonat:

There is a need to improve Austroads procedures for the structural design of pavements containing lightly bound cemented (LBC) materials. This report describes the findings of an investigation of the performance of Queensland pavements with LBC bases. It describes the construction and performance monitoring of two trial sections from which in situ LBC moduli were estimated. Laboratory testing was undertaken to improve understanding of the cracking characteristics of LBC materials compared to heavily bound cemented (HBC) materials. Unconfined compressive strength requirements for LBC materials are proposed. A structural design method was developed for pavement containing LBC materials and HBC materials in the post-cracking phase of life.

Az ausztrál gyalogos tervezési útmutató felújítása a nemzetközi legjobb gyakorlat alapján

Updating Austroads Pedestrian Planning and Design Guidance in line with International Best Practice

Szerző(k): J. Ward, A.M. Head, T. Fleming, C, Munro, Dave Smith

letölthető ingyenes regisztrációval

Terjedelem: 85 oldal

Kivonat:

This report details the results of a review of Austroads guidance to ensure that Australian and New Zealand state and local governments have access to up-to-date pedestrian planning and design information that reflects national and international good practice. The Guide to Traffic Management (AGTM) and Guide to Road Design (AGRD) series were reviewed with respect to current pedestrian planning and design guidance. A practitioner industry survey informed this review. The aim of the survey was to understand the current use of the Austroads guides by practitioners, identify what is useful and what is missing from the guides in terms of pedestrian planning and design, and help inform the development of recommendations for updates to the existing guides. A total of 120 planning and design gaps were identified. Recommended changes to the AGTM were published in April 2020. Recommended changes to the AGRD have been reviewed and approved by the Road Design Task Force and will find their way into the AGRD as part of its update and restructure planned by the Road Safety & Design program in FY20-21.

Javított forgalom menedzsment útmutató: gyorsforgalmi utak kapacitás elemzése

Improved Traffic Management Guidance: Freeway Capacity Analysis

Szerző(k): P. Bennett, F. Naznin