• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.7 no.1
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• pp.127-136
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• 2008

In these days, frequency of constructions on e freeway are increasing according as growing of the importance of e road maintenance and the road management. Work zone on the freeway where vehicles pass with high speed needs control method of lane closure and construction equipment. Because there are seldom researches in domestic study about reflecting characteristics of domestic road, sometimes we have applied for foreign cases to our traffic circumstance but it is not proper to apply for standard of other countries in our cases. foreign nation has different country square, condition of road, and level of people mind. Therefore, this study shows traffic accident characteristics in freeway work zones in Korea. At first, this study collected traffic accident data which include for 3 years $2003{\sim}2005$ in the whole freeway in Korea and then divided the data to five parts - level of the accident, type of the construction work, type of the accident, reason of the accident, according to geometric. According to comparing with non-work zones accident, this study found traffic accident characteristics in freeway work zones in Korea and suggested some alternative ideas for safety of work zones.

• Journal of Korean Society of Transportation
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• v.35 no.4
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• pp.278-291
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• 2017

Effective installation and operations of traffic safety signs in the advance warning area is of considerable interest for safer traffic management at freeway work zones. This study evaluated the feasibility of traffic safety sign installation based on a driving simulation experiment to take drivers' responsive characteristics into consideration. Both the compliance rate for speed limit and a lane-changing safety index were used for evaluating a set of driving simulation scenarios. It was identified that providing speed limit signs to reduce speed in advance and afterward guiding lane-changing could lead to safer maneuvering of vehicles entering work zones. The outcomes of this study are expected to be useful for revising freeway work zone management policies toward crash prevention.

• Journal of Korean Society of Transportation
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• v.34 no.4
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• pp.354-372
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• 2016

This study identified factors affecting the crash severity at freeway work zones. A nice feature of this study was to take into account the characteristics of work zone traffic management in analyzing traffic safety concerns. In addition to crash records, vehicle detection systems (VDS) data and work zone historical data were used for establishing a dataset to be used for statistical analyses based on an ordered probit model. A total of six safety improvement strategies for freeway work zones, including traffic merging method, guidance information provision, speed management, warning information systems, traffic safety facility, and monitoring of effectiveness for countermeasures, were also proposed.

• Journal of the Korean Society of Industry Convergence
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• v.5 no.4
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• pp.329-337
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• 2002

It is the actual condition that the increasing traffic delay and accident caused by inefficient management on various construction by occupying the roadways. Since almost roadway improvements are for the public convenient, negative effects by them are ignored. But now due to the increase of traffics demand and limitation of road supply, the positive management scheme and treatment plan on the constructions must be considered. Thus, to the extent of this study divides uninterrupted flow into freeways and the Highway, yielding the time spread between under construction and not, that is delay time, we build capacity and delay model in the change of traffic volume and occupying length.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.15 no.4
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• pp.91-103
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• 2016

The work zone traffic management is of keen interest because the unstable traffic stream in work zones leads to not only less productive traffic operational efficiency but also negative impacts on traffic safety. A promising method to address such issues is variable speed limit systems(VSLS). VSLS is expected to increase in throughput and to enhance safety by diminishing the crash potential. In addition, the usefulness of VSLS has been demonstrated by significant amount of existing literature. The objective of this study is to identify the effectiveness of VSLS based on a meta analysis technique. Throughput and travel speed were used as measures of effectiveness for VSLS in terms of the operational efficiency and safety respectively. Results showed that approximately 16.4% increase in throughput and 16.5% decrease in travel speed were obtainable by VSLS. The outcomes of this study would be useful in developing technologies and polices for better operation of VSLS.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.19 no.3
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• pp.38-51
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• 2020

A bottleneck and congestion occur when a freeway is closed due to maintenance and construction activities on the freeway. Although various traffic managements have been developed to improve the traffic efficiency at freeway work zones, such as merge control, there is a limit to those controls with human drivers. On the other hand, the wireless communication of connected and automated vehicles (CAVs) enables the operation of advanced traffic management. This study developed a traffic control strategy that integrates Dynamic Merge Control (DMC) and Lane Change Control (LCC) in a CAV environment. DMC operates as an either early or late merge based on the occupancy rate of upstream of the work zone. The LCC algorithm determines the number of vehicles that need to change their lane to balance the traffic volume on open lanes. The simulation results showed that integrated control improves the cumulative vehicle count, average speed upstream, and average network travel time.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.19 no.2
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• pp.48-61
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• 2020

The objective of this study is to estimate traffic capacity based on the heavy-vehicle ratio in a two-lane freeway work zone where one lane is blocked by construction. For this, closed circuit television (CCTV) video data of the freeway work zone was collected, and the congestion at an upstream point was observed. The traffic volume at a downstream point was analyzed after a bottleneck was created by the blockage due to the upstream congestion. A distribution model was estimated using observed-time headway, and the road capacity was analyzed using a goodness-of-fit test. Through this process, the general capacity and an equation for capacity based on the heavy-vehicle ratio passing through the work zone were presented. Capacity was estimated to be 1,181~1,422 passenger cars per hour per lane (pcphpl) at Yeongdong, and 1,475~1,589pcphpl at Jungbu Naeryuk. As the ratio of heavy vehicles increased, capacity gradually decreased. These findings can contribute to the proper capacity estimation and efficient traffic operation and management for two-lane freeway work zones that block one lane due to a work zone.

• International conference on construction engineering and project management
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• 2007.03a
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• pp.269-278
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• 2007

Nighttime construction is being adopted by many state DOT's as a way to mitigate the impact of construction operations on the traveling public. Although a number of states have developed standard specifications for nighttime lighting, these standards are usually in the form of generic requirement statements that only specify minimum illuminance levels. The lighting standards do not include specific ways to achieve this illuminance level such as lighting arrangements and configurations for various work zone plans and construction operations. This leaves confusion between the traffic engineers and the contractors and does not guarantee consistency in those plans, thus affecting productivity and safety (lighting conditions account for 18% to 28% of work zone accidents). The main objective of this study is to utilize three dimensional animation and lighting analysis software to study and model lighting conditions of a construction site. This is expected to increase the safety and productivity of construction operations by achieving consistency in work zone lighting schemes. A computerized model was developed, called Nitelite. Various lighting schemes can be studied using the software to provide for typical applications including lighting fixture's locations, luminance, mounting height, tilt angle, and fixture type. The results from the developed software tool were validated through comparisons with previous research conducted using field measurements.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.33 no.3
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• pp.1123-1130
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• 2013

This paper aims to estimate work zone base capacity by the number of lanes for urban freeway. To do this, data were collected from the field survey and the database system maintained by traffic control center, and analyzed with four different methods such as the average maximum observation flow rate, headway, regression analysis, and parameter inspection. The work zone base capacity for urban freeway is estimated based on the average maximum observation flow rate and headway method, which are more reliable methods compared to others. The average capacity is 1,650pcphpl when the design speed is 80km/h. The capacity of four lanes one-way work zones was about 1,700pcphpl, while one of 2 lanes one-way work zones was about 1,600pcphpl. The capacity reduction rates for each are 0.15 and 0.2, respectively. The smaller the number of lane is, the more base capacity is reduced. For verification of results, we estimate the capacity by simulation analysis using PARAMICS, and compare with analytical results by a statistical method. This research can be used for efficient and systemic management of work zone in the urban freeway.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.38 no.6
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• pp.867-878
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• 2018

As the era of AVs (Automated Vehicles) comes to a close, many researches related to AVs have been conducted. Up until now, research on traffic flow impact of AVs has been the main topic, and research on traffic management for AVs is still in beginning stage. This study analyzed the effect of Dynamic Merge Control (DMC) in manual vehicle (MV) and AV environment at work zone. Dynamic Late Merge (DLM) and DLM with Dynamic Early Merge (DEM) are compared by simulation. Simulation results showed that DLM improves travel time and work zone throughput compared to no merge control case in both MV and AV environment. In the case of additional operation of DEM, the improvement effect was not observed in MV environment, but it was improved in AV environment. As a result, DMC operation in AV environment was as effective as the improvement in transition from MV to AV environment. Therefore congestion reduction at freeway work zone by DMC will be possible in future AV environment, and the improvement of DMC can be suggested.