May 2007 - Vol. 14 No.1
From REAAA Wiki
- The Effect of Flexible Toll Measures and Optimal Layout of Smart Interchanges on the Japan Expressway Network
- Mathematical Modelling of Freeway Ramp Merging Capacity Anaylsis Based on Revised Headway Distribution Model
- Life Cycle Analysis for Japanese Expressway Pavements
- The Use of Illegal Passenger Van Services in Bangkok
- Axle Load Equivalencies and the Effect of Wide Single and Dual Tyres on the Performance of Granular Pavements
- Development of Rapid Construction Methods for Over-Bridge Crossing System
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Chairman REAAA Technical Committee
This first issue of the REAM Journal for 2007 contains six papers. These papers were awarded Katahira Awards at the 12th REAAJA Conference held in Manila, Philippines, in November 2006. The Award is in honour of the late Dr Nobutaka Katahira, a former President of REAM, who set up a trust fund to encourage the professional development of young engineers in the region. A judging panel was assigned to review eligible papers and make recommendations regarding the awards.
The first paper, by Yukihiro Tsukada, Waka Matsuda and Kenta Hamaya of the Ministry of Land, Infrastructure and Transport (MLIT), Japan, was awarded the Katahira Award for the best paper at the REAAA Conference. The paper describes a study conducted by the MLIT which examined the effects of flexible toll measures and the optimal layout of smart interchanges on traffic using the Japan expressway network. The analysls of the results obtained from demonstration projects suggested that the toll rate policy would be more efficient if it was set to specific time zones, such as commuting hours or nighttime travel; appropriate time zones for policy implementation varied depending on the traffic characteristics; and greater efficiency would be achieved by selecting sections where policy implementation is likely to be particularly effective.
The second paper, by Seungjun Lee ofthe Korea Highway Corporation, was awarded the runner-up Katahira Award for outstanding paper at the Conference. In this study, an attempt was made to redefine the headway distribution at a freeway ramp merging area taking account of the effects of merging behaviour on freeway merging capacity calculations. Models for the calculation of merging capacity were developed which consider both freeway mainline and ramp flows. A sensitivity analysis was conducted to examine the impacts of different volume levels on freeway ramp merging capacity.
The next four papers were each awarded a Katahira Award for 'highly commended' paper at the REAAA Conference.
The Japan Highway Public Corporation has been responsible for the construction, operation and maintenance of the nation-wide toll expressways on behalf of the Japanese Government since 1956. In 2005 it was privatised, and three regional expressway companies (NEXCO) were formed. This paper describes the work undertaken by NEXCO to develop a pavement management system for the prediction of pavement performance, including life cycle costing (LCC). When the LCC models were applied to one section of the network, the durability of porous asphalt was about 1.2 times to 1.5 times higher than that of dense-graded asphalt, suggesting that the porous pavement is an excellent option for the rehabilitation of pavements about ten years of age or older. Ride quality is becoming an increasingly important issue on Japanese expressways. For this reason, NEXCO has also been investigating the applicability of the International Roughness Index (lRl) to assess the ride qualig of its network and to assist in the setting of limits for its safe and efficient operation.
In 1999, the Government of Malaysia regulated passenger van services in Bangkok to assist in the provision of safe public transport to commuters and to reduce competition between passenger vans and conventional buses. However, a large number of illegal vans still operate along the licensedroutes. The objectives of the study described in the fourth paper were to investigate the level-of- service attributes of public transit users in general, and illegal passenger van users in particular, and to use these fifdings in the planning of future services. The three main reasons why respondents preferred to use the passenger van service were related to time, convenience, and comfort. lvlost respondents were unaware that the vans they were using were operating illegally because their characteristics and services were similar to the legal passenger vans.
The next paper describes work currently being conducted byARRB Research to improve knowledge of the efiects of axle load and tyre type on the deterioration of unbound granular pavements surfaced with a thin bituminous seal, the most common pavement type in Australasia. The two specific objectives ofthe research were to determine the applicability of the'fourth power law'to these types of pavements and to assess the relative damaging effects of wide single and steer axle tyres compared to dual tyres for Australasian pavement types.
Serious traffic congestion at intersections has become a critical issue in Japan. The final paper describes a system developed by the Japan Bridge Association for the rapid construction of over- bridge crossings to minimise traffic restrictions, reduce construction costs, and minimise environmental impacts. An outline of the rapid construction method is presented, together with two case studies.
The Editorial Panel continues to seek papers and technical notes for publication rn the Journal. The membership of the Editorial Panel follows. REAM members interested in submitting a paper should seek advice from the appropriate member(s) of the Editorial Panel. The Panel is striving to publish at least one paper from each Chapter or region each year.