Papers by Sorawit Narupiti

Asian transport studies, 2014
Social Networking Services (SNSs) attract much attention as media for collecting disaster informa... more Social Networking Services (SNSs) attract much attention as media for collecting disaster information. Many studies have been conducted regarding the effect of SNSs on people's behavior during disasters. However, there are few studies that deal with the relationship between daily SNS usage and people's behavior during disasters. Based on a questionnaire survey in Bangkok, the relationship was analyzed using Structural Equation Modeling and the Theory of Planned Behavior. It was found that attitudes toward the collection of information in daily life had some influence on the intention to collect disaster information. Additionally, confidence in their ability to select correct information had crucial influence on whether or not to increase SNS usage. It was concluded that SNSs have some potential as interactive media. That is, they should be used not only for collecting but also for providing information. Language: en

KMUTT Research and …, 2004
ÿ «-®™-¬ ‡ªÑ "ª√-¬Ÿ √ 1 ª√ÿ ß®-π∑√å «ß»å «' ‡»… 2 ∫-≥±' µ«' ∑¬"≈-¬√à «¡¥â "πae≈-ßß"π•≈-' Ë ß•«¥≈â... more ÿ «-®™-¬ ‡ªÑ "ª√-¬Ÿ √ 1 ª√ÿ ß®-π∑√å «ß»å «' ‡»… 2 ∫-≥±' µ«' ∑¬"≈-¬√à «¡¥â "πae≈-ßß"π•≈-' Ë ß•«¥≈â Õ¡ ¡À"«' ∑¬"≈-¬ ‡∑ §‚π‚≈¬' ae√-®Õ¡ ‡°≈â "∏π∫ÿ √' ∫"ß¡¥ ∑ÿ à ß §√ÿ °√ÿ ß ‡∑aeoe 10140 √«' » πƒªî µ' 3 ®ÿ Ã"≈ß°√≥å ¡À"«' ∑¬"≈-¬ ∂.ae≠"‰∑ ª∑ÿ ¡«-π °√ÿ ß ‡∑aeoe 10330 ‡Õ° "√ß"π«' ®-¬π' È ‡ πÕ«' ∏'°"√ ‡°Á ∫¢â Õ¡Ÿ ≈•≈-°"√ √â "ß•∫∫®"≈Õß√-¥-∫ ‡ ' ¬ßÕâ "ßÕ' ߢÕß√∂¬πµå "πª√-‡∑» ‰∑¬"π ¿"ae°"√‰À≈•∫∫‰¡à µà Õ ‡π◊ Ë Õß ´÷ Ë ß ‡ªì π∞"π¢â Õ¡Ÿ ≈∑' Ë " §-≠Õ¬à "߬' Ë ß"π°"√∑"π"¬ ‡ ' ¬ß®√"®√∑' Ë ∫√' ‡«≥ ' Ë •¬°‚ ¥¬√-¥-∫ ‡ ' ¬ßÕâ "ßÕ' ß•∫à ßÕÕ° ‡ªì π 8 ª√-‡¿∑µ"¡ª√-‡¿∑¢Õß√∂¬πµå ∑-È ß 8 ™π' ¥ ´÷ Ë ß‰¥â •°à √∂¬πµå à «π∫ÿ § §≈ √∂°√-∫-√∂∫√√∑ÿ°À°≈â Õ √∂∫√√∑ÿ° ' ∫≈â Õ √∂aeà «ß √∂‚¥¬ "√ √∂®-°√¬"π¬πµå •≈-√∂ "¡≈â Õ ‡ §√◊ Ë Õß ¢â Õ¡Ÿ ≈ π"¡∑' Ë ‡°Á ∫‰¥â •°à √-¥-∫ ‡ ' ¬ß•≈-§«"¡ ‡√Á «¢Õß√∂¬πµå ∑' Ë µ"•Àπà ß 15, 30, 60, •≈-120 ‡¡µ√ ®"°µ"•Àπà ß À¬ÿ ¥ ‚¥¬µ' ¥µ-È ß ‡ §√◊ Ë Õß«-¥ ‡ ' ¬ß®"π«π 4 ‡ §√◊ Ë Õß∑' Ë µ"•Àπà ߥ-ß°≈à "« •≈-Àà "ß®"°°÷ Ë ß°≈"ß™à Õß®√"®√ ‡ªì π√-¬-15 ‡¡µ√ √-¥-∫ ‡ ' ¬ß•≈-Õ-µ√" ‡√Á «∑' Ë ‰¥â ®"°∑-È ß 4 ®ÿ ¥®-π"¡" √â "ß ¡°"√ §«"¡-¡ae-π∏å ‚¥¬√-¥-∫ ‡ ' ¬ß®-‡ªì πµ-«•ª√ µ"¡•≈-Õ-µ√" ‡√Á « ‡ªì πµ-«•ª√Õ' √-‚¥¬"™â ¡°"√¢Õß°√¡∑"ßÀ≈«ß¢Õß À√-∞Õ ‡¡√'°" The development of basic noise emission levels for vehicles in Thailand in the condition of interrupted traffic flow is presented in this paper. The basic noise emission levels are classified into 8 classes in accordance with the following vehicle types: passenger car, light truck, medium truck, heavy truck, tractor trailer, bus, motorcycle, and Tuk-tuk. The maximum A-weighted sound levels (L AFmx) of accelerating vehicles and corresponding speeds were collected from several individual pass-by vehicles in Bangkok and other provinces. Four sound level meters were situated at the distances of 15, 30, 60 and 120 meters from the imaginary stop line with 15 meters setback from the centerline of the nearest travel lane for the measurement of maximum sound levels at the fronts of all instruments. The vehicular instantaneous speeds at the same locations with L AFmx measurement were also measured. The L AFmx of eight types of vehicles were then plotted against the corresponding speeds to determine their relationship. The results indicate that the eight vehicle types are significantly different in their acoustical features. Furthermore, the resulting basic noise emission levels are significantly different from those in the FHWA Traffic Noise Model (FHWA TNM) due to the country-to-country differences in vehicle characteristics.

Travel Time Estimation and Prediction for Urban Arterial Roads
Travel time information has been accepted as the core of advanced traveler information systems (A... more Travel time information has been accepted as the core of advanced traveler information systems (ATIS) and advanced traffic management systems (ATMS). Providing the accurate travel time information to traffic operators and travelers allows them to make informed decisions, leading to more advantage for individual road users and the entire transportation system. Most of the traffic information providers normally deliver the current traffic conditions or current travel times to public assuming the state of traffic remains constant in the near future. Aimed at the more effective applications, short-term future traffic conditions have been proposed as a valuable piece of information in ATIS and ATMS, apart from instantaneous or estimated travel time for representing current traffic conditions. This dissertation aims at formulating the approaches for travel time estimation and short-term travel time prediction using probe data. The urban roadways in CBD area of Bangkok metropolis with high...

Advanced Traveler Information System (ATIS) has been applied in many countries because it has bee... more Advanced Traveler Information System (ATIS) has been applied in many countries because it has been proved as one of potential solutions to solve congestion problem and to improve the quality of driving. Providing drivers with additional traffic information, it is expected to influence their travel decision on route and destination selection, or even on cancellation of the trip. A number of studies have been conducted in order to improve the performance of ATIS in various ways, such as the setting of the system, the content of information, the accuracy of the information, etc. Yet the effectiveness of the system is heavily dependent on the driver's behavior and response to the given information. The behaviors are somewhat unique for specific individuals (cities). The primary objective of this study wais to analyze the behavior of drivers in different South East Asia major cities; Bangkok (Thailand), Kuala Lumpur (Malaysia), and Singapore (Singapore), pertaining changing route und...

To develop an actuated traffic-signal-control method that has ability to efficiently manage traff... more To develop an actuated traffic-signal-control method that has ability to efficiently manage traffic, especially oversaturation, by considering not only present situation in only small area but also considering the effect to the whole network in nearly future and to compare effectiveness with some other methods. This method focuses on maximizing overall throughput of the system. The scope of study covers two parts which are developing and testing the method in some different levels of traffic. The method is developed and it is tested on a computer-simulated corridor with four intersections compared to fixed-time method with and without prevention of green-time loss. The tool used in the test is a micro-simulation program, named Paramics. The results, which are number of vehicles containing in the system, average green time given to each link during a peak hour, destination arrival, real-time throughput, real-time average speed in the system, total travel time, and peak throughput, ar...
Valuing Passenger Van Service in Bangkok Based on Stated Preference Surveying Techniques
Journal of the Eastern Asia Society for Transportation Studies, 2007
In the recent years, passenger van is a new form of the small-medium transit service in Bangkok. ... more In the recent years, passenger van is a new form of the small-medium transit service in Bangkok. In comparison to bus, passenger van offers shorter journey time, increased headway, improved reliability, higher levels of comfort, less frequent stopping, ...
Testing traffic control strategies for incident congestion management of a surface street system
Quality of probe vehicle data on travel time estimation
Incident Management
Selecting the most appropriate traffic control strategy for incident congestion management can ha... more Selecting the most appropriate traffic control strategy for incident congestion management can have a major impact on the extent and duration of the resulting congestion. This research investigated the effectivenesses of several control strategies on various incident conditions. The selected control strategies representing possible ITS technologies included traffic metering (ATMS), traffic diversion (ATIS), and traffic diversion with signal timing modification (ATIS/ATMS). The analysis was conducted on a hypothetical dense grid sur- face street network. Mid-block incidents of various durations were tested. The results indicated that the ATIS/ATMS based solution can reduce congestion duration up to 27 minutes, with a saving of 261 vehicle- hours of delay. A sensiti...

Journal of the Eastern Asia Society for Transportation Studies, 2010
The Advanced Traveler Information System (ATIS) has been applied in many countries because it has... more The Advanced Traveler Information System (ATIS) has been applied in many countries because it has been proved as one of potential solutions to solve congestion problem and to improve the quality of driving. Providing drivers with additional traffic information, it is expected to influence their travel decision on route and destination selection, or even on cancellation of the trip. A number of studies have been conducted in order to improve the performance of ATIS in various ways, such as the setting of the system, the content of information, the accuracy of the information, etc. Yet the effectiveness of the system is heavily dependent on the driver"s behavior and response to the given information. The behaviors are somewhat unique for specific individuals (cities). The primary objective of this study was to analyze the behavior of drivers in different Southeast Asian major cities; Bangkok (Thailand), Kuala Lumpur (Malaysia), and Singapore (Singapore), pertaining to changing ro...

Planning for Better Mobility in Southeast Asian Region: A Case Study of Asean Highway and Singapore-Kunming Rail Link
The Association of Southeast Asian Nations (ASEAN) progresses two major land transport projects; ... more The Association of Southeast Asian Nations (ASEAN) progresses two major land transport projects; ASEAN Highway and Singapore-Kunming Rail Link (SKRL). These projects are not only inter-connecting nations in the region with transport infrastructure. The developments of the projects are reviewed in this paper. The steps toward cooperation, agreement, plan formulation, and roads to implementation are critically examined. ASEAN Highway is generated from the mutual cooperation on the integration into strong region. The project is gradually progressed according to a plan of action. SKRL is an international rail transport connection with prospect benefits for economic cooperation within the region. The plan is at the early development stage and promisingly requires more elaboration on several development issues. The findings from their developmental exercises expose the understanding on the movement of the international development activities and lessons for prospect of better development.

Bangkok Traffic Monitoring System
Traffic data is essential for determining better traffic management and providing valuable inform... more Traffic data is essential for determining better traffic management and providing valuable information to drivers. Especially to tackle traffic congestion, traffic data is needed to understand traffic patterns, and to come up with proper solutions for congestion alleviation. In Bangkok, many authorities are involved with the management of traffic, and in recent years, Royal Thai Police has installed a comprehensive image processing detector system throughout Bangkok, in order to monitor traffic. This paper describes Bangkok traffic monitoring system of Royal Thai Police. The system consists of 152 image processing cameras installed at 45 intersections and central unit at a traffic control center. The detectors are capable of providing traffic volume, speed, queue length, and traffic image. All the cameras are linked to the Central Traffic Control and Command center, where the data are stored and made available to operators and commanders. A set of traffic data from the system was an...
Evaluation of Offline and Online Speed-based Travel Time Estimation on Expressway

Journal of the Eastern Asia Society for Transportation Studies, 2015
Due to more complicated behavior than controlled access roadway, congested estimation on arterial... more Due to more complicated behavior than controlled access roadway, congested estimation on arterial road network has become a challenging topic for all traffic professionals in recent years. To indicate the traffic condition, link travel speed is considered as one of the important markers for representing traffic status on roadway network and most understood pointer for all road users. This paper describes the implementation of Running Speed and Stopped Delay (RSSD) technique for investigating the urban link travel speed and discusses on the limitation of error in speed associated from each global positioning system (GPS) device to maintain the advantages of proposed technique in travel speed estimation. The results from real observation traffic data on urban roadway also confirm that the accuracy of travel speed estimation is significantly improved when RSSD was employed as the estimation technique compared to baseline approach particularly in the links with highly congested condition.
Quality of Travel Time Estimation from Probe Vehicles: A Simulation Study
Journal of the Eastern Asia Society for Transportation Studies, 2007
Dynamic Travel Time Estimation using On-line Microsimulation on Expressway for Advance Traveler Information System

The aim of this study is to discuss the feasibility of a system to collect traffic information us... more The aim of this study is to discuss the feasibility of a system to collect traffic information using probe vehicles in a developing city in terms of cost efficiency. Firstly, the field test that applied five taxies as probe vehicles in Bangkok was conducted to identify their running performance and characteristics. Secondly, based on the result of field test, a micro simulation model was developed to verify the minimum number of probe vehicles that can ensure sufficient data collecting information from which reliable average travel time can be calculated. Finally, to estimate the cost of system, the amount of transmitted data from probe vehicles was calculated when probe vehicles collected traffic information dynamically applying the minimum number of probe vehicles. As a result, it was found that average travel time of all vehicles can be estimated in every 15 minutes at half of all road sections in Bangkok, if all taxis can be used as probe vehicles.

A Novel Approach of Dynamic Time Warping for Traffic Congestion Detection and Short-Term Prediction
The objective of this study is to develop a new automated short-term traffic congestion detection... more The objective of this study is to develop a new automated short-term traffic congestion detection algorithm that can detect traffic patterns leading to congestion in microscopic traffic variables. A new approach algorithm, namely Dynamic Time Warping, is different from traditional artificial intelligent algorithms that require a large training dataset to satisfy the accuracy. The Dynamic Time Warping has much more ability to classify in very complex time series but requires a much smaller training dataset while yielding high accuracy in result. The performance of the proposed algorithm is assessed using a Bayesian algorithm with a microscopic traffic simulation environment and real-world data. The result shows that the new proposed algorithm has comparable performance to the Bayesian algorithm with using the standard deviation of speed as algorithm figures to detect and precursor traffic congestion pattern. The proposed algorithm also performs very well even when applied to real-wor...
Incident Management: FAST-TRAC Phase IIB Deliverables. No. 20. The Model Analysis Report on the Benefits of SCATS in Alleviating the Impacts of Incidents
Selecting the most appropriate traffic control strategy for incident congestion management can ha... more Selecting the most appropriate traffic control strategy for incident congestion management can have a major impact on the extent and duration of the resulting congestion. This research investigated the effectiveness of several control strategies on various incident conditions. The selected control strategies representing possible ITS technologies included traffic metering (ATMS), traffic diversion (ATIS), and traffic diversion with signal timing modification (ATIS/ATMS). The analysis was conducted on a hypothetical dense grid surface street network.

Investigating Travel Behavior Associated with the Introduction of Car-Sharing System in Bangkok
A study of the potential use of a new transportation mode often challenges transport planners in ... more A study of the potential use of a new transportation mode often challenges transport planners in forecasting future demands. Various factors influence travelers on making decision, especially attitudes, demography, and travel characteristics leading to, if not properly examined, unreliable demand forecasting. A Car-sharing system is an innovative transportation mode for Bangkok people to shift from an existing mode. This paper focuses on a study of the travelers' opinion on the new mode and the potential use of the Car-sharing system in Bangkok regarding pre- and post- attitudes toward the system. A two-phase analysis of a preliminary study and an attitude-related research are conducted to elicit travel behavior information associated with an introduction of the Car-sharing system. Descriptive and conductive statistics are presented for describing the relationship between the level of interests and the travelers' explanatory characteristics. The study develops a methodology ...
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Papers by Sorawit Narupiti