Deterministic and Stochastic Capacity in Work Zones: Findings from a Long-Term Work Zone

2021 ◽  
Vol 147 (1) ◽  
pp. 04020141
Author(s):  
Jalil Kianfar ◽  
Saber Abdoli
Author(s):  
Bekir Bartin ◽  
Kaan Ozbay ◽  
Matthew D. Maggio ◽  
Hao Wang

Faced with a growing number of work zones, transportation agencies are being challenged to effectively manage the impacts of these zones, alleviate congestion, and maintain the safety of motorists and workers without disrupting project schedules. Coordinating work zones has already been practiced by various state departments of transportation and transportation agencies, yet there are no universal department of transportation policies that address how agencies should coordinate or consolidate projects. In addition, only a few states utilize computer tools specific to regional or corridor-based work zone coordination. State departments of transportation mostly coordinate significant and long-term projects. However, the majority of roadway projects include minor repair, roadway maintenance, bridge maintenance, surveying, and landscape and utility work that require relatively short-term work zones. The Work Zone Coordination Software tool was developed to provide the New Jersey Department of Transportation with an easy-to-use tool to evaluate the feasibility and effectiveness of coordinating short- and long-term work zones and to measure the benefits. This online tool is implemented with a web-based user interface. It integrates all scheduled and active construction projects, identifies conflicts between work zone projects, and estimates the benefits of conflict mitigation. The Work Zone Coordination Software tool works with the New Jersey work zone database by automatically importing data to provide up-to-date information to its users. However, the tool is built on a flexible framework that allows the integration of any work zone database provided that it includes all the required information.


2018 ◽  
Vol 29 (2) ◽  
pp. 19-36
Author(s):  
Nawaf M. Alshabibi Nawaf M. Alshabibi

This paper assesses the impact of long-term work zones in arterial roads on commercial activities in Dammam Metropolitan area. The study focuses on two cases of long-term work zones in arterials in two major cities in Dammam Metropolitan Area. The first case is a work zone with full lanes closure on Prince Mohamed Bin Fahad Road at the south east entrance of Dammam city. The second case is a work zone with full lanes closure on King Abdul-Aziz Road at the northern entrance of Al-Khobar City. Data collection relies on field survey including questionnaires to affected business owners and managers. The questionnaire has been developed to assess the impact before and during road works period, in the work zone, on mobility and accessibility to commercial activities. Field survey includes 201 commercial activities at two work zone locations. Answers have been registered in Excel spreadsheet. Data analysis includes percentages of change, means, and standard deviation of dependent variables before and during the presence of the work zone. It was found that long-term work zones on arterials have multiple negative impacts on workers, sales, and customers. These impacts are related to lack of mobility, accessibility and reduction of parking availability during work period. Also, restaurants and travel agencies were the most effected activities by work zone presence, while banks were the least effected.


2018 ◽  
Vol 2018 ◽  
pp. 1-15 ◽  
Author(s):  
Chaoru Lu ◽  
Jing Dong ◽  
Anuj Sharma ◽  
Tingting Huang ◽  
Skylar Knickerbocker

Speed-volume-density relationship and capacity are key elements in modelling traffic operations, designing roadways, and evaluating facility performance. This paper uses a modified five-parameter logistic model to describe the speed-density relationship. The calibrated speed-density models show that the stop-and-go speed (Vb) and shape parameters (θ1 and θ2) are similar for work zones and the nonwork zone site. Accordingly, an operational capacity prediction method is proposed. To demonstrate the effectiveness of the proposed method, the predicted operational capacities are compared with the field data, Highway Capacity Manual method, the output of WorkZoneQ software, and the ensemble tree approach under different work zone scenarios. Furthermore, a lifetime distribution prediction framework for stochastic capacity of work zones is proposed. The predicted lifetime distribution can well capture the tendency of the observed work zone capacities.


Author(s):  
Ana Maria Elias ◽  
Zohar J. Herbsman

Construction sites or work zones create serious disruptions in the normal flow of traffic, resulting in major inconveniences for the traveling public. Furthermore, these work zones create safety hazards that require special consideration. Current legislation and programs, at both state and national levels, emphasize the need for a better understanding of work zone problems to address work zone safety. This reality—coupled with the temporary closure of more miles of highway every year for rehabilitation and maintenance—makes the analysis of safety at construction sites a serious matter. A summary of a comprehensive study associated with the development of a new practical approach to address highway safety in construction zones is presented. Because empirical models require sample sizes that are not attainable due to the intrinsic scarcity of construction zone accident data, the problem was studied from the point of view of risk analysis. Monte Carlo simulations were used to develop risk factors. These factors are meant to be included in the calculations of additional user costs for work zones, or simply applied as risk measurements, to optimize the length and duration of closures for highway reconstruction and rehabilitation projects. In this way, it will be possible to assess the danger of work zones to the traveling public and minimize adverse effect of work zones on highway safety.


Author(s):  
Michelle M. Mekker ◽  
Yun-Jou Lin ◽  
Magdy K. I. Elbahnasawy ◽  
Tamer S. A. Shamseldin ◽  
Howell Li ◽  
...  

Extensive literature exists regarding recommendations for lane widths, merging tapers, and work zone geometry to provide safe and efficient traffic operations. However, it is often infeasible or unsafe for inspectors to check these geometric features in a freeway work zone. This paper discusses the integration of LiDAR (Light Detection And Ranging)-generated geometric data with connected vehicle speed data to evaluate the impact of work zone geometry on traffic operations. Connected vehicle speed data can be used at both a system-wide (statewide) or segment-level view to identify periods of congestion and queueing. Examples of regional trends, localized incidents, and recurring bottlenecks are shown in the data in this paper. A LiDAR-mounted vehicle was deployed to a variety of work zones where recurring bottlenecks were identified to collect geometric data. In total, 350 directional miles were covered, resulting in approximately 360 GB of data. Two case studies, where geometric anomalies were identified, are discussed in this paper: a short segment with a narrow lane width of 10–10.5 feet and a merging taper that was about 200 feet shorter than recommended by the Manual on Uniform Traffic Control Devices. In both case studies, these work zone features did not conform to project specifications but were difficult to assess safely by an inspector in the field because of the high volume of traffic. The paper concludes by recommending the use of connected vehicle data to systematically identify work zones with recurring congestion and the use of LiDAR to assess work zone geometrics.


Author(s):  
Mustafa Suhail Almallah ◽  
Qinaat Hussain ◽  
Wael K. M Alhajyaseen ◽  
Tom Brijs

Work zones are road sections where road construction or maintenance activities take place. These work zones usually have different alignment and furniture than the original road and thus temporary lower speeds are adopted at these locations. However, drivers usually face difficulty in adopting the new speed limit and maneuvering safely due to the change in alignment. Therefore, work zones are commonly considered as hazardous locations with higher crash rates and severities as reported in the literature. This study aims to investigate the effectiveness of a variable message signs (VMSs) based system for work zone advance warning area. The proposed system aims at enhancing driver adaptation of the reduced speed limit, encourage early lane changing maneuvers and improve the cooperative driving behavior in the pre-work zone road section. The study was conducted using a driving simulator at the College of Engineering of Qatar University. Seventy volunteers holding a valid Qatari passenger car driving license participated in this study. In the simulator experiment, we have two scenarios (control and treatment). The control scenario was designed based on the Qatar Work Zone Traffic Management Guide (QWZTMG), where the length of the advance warning area is 1000 m. Meanwhile, the treatment scenario contains six newly designed variable message signs where two of them were animation-based. The VMSs were placed at the same locations of the static signs in the control scenario. Both scenarios were tested for two situations. In the first situation, the participants were asked to drive on the left lane while in the second situation, they were instructed to drive on the second lane. The study results showed that the proposed system was effective in motivating drivers to reduce their traveling speed in advance. Compared to the control scenario, drivers’ mean speed was significantly 6.3 and 11.1 kph lower in the VMS scenario in the first and second situations, respectively. Furthermore, the VMS scenario encouraged early lane changing maneuvers. In the VMS scenario, drivers changed their lanes in advance by 150 m compared to the control scenario. In addition, the proposed system was effective in motivating drivers to keep larger headways with the frontal merging vehicle. Taking into account the results from this study, we recommend the proposed VMS based system as a potentially effective treatment to improve traffic safety at work zones.


Author(s):  
Andrew Berthaume ◽  
Lauren Jackson ◽  
Ian Berg ◽  
Brian O’Donnell ◽  
Christopher L. Melson

Central to the effective design of work zones is being able to understand how drivers behave as they approach and enter a work zone area. States use simulation tools in modeling freeway work zones to predict work zone impacts and to select optimal design and deployment strategies. While simple and complex microscopic models have been used over the years to analyze driver behavior, most models were not designed for application in work zones. Using data collected from an instrumented research vehicle and model components from two PhD dissertations, FHWA created the Work Zone Driver Model and programed the Work Zone Driver Model DLL v1.0, a software that could override car-following in commercial microsimulation software packages so that practitioners can better predict work zone impacts. This paper demonstrates the capabilities of the FHWA Work Zone Driver Model DLL v1.0, interfaced with VISSIM and tested on an Interstate work zone in Springfield, Massachusetts. The dynamic link library’s (DLL’s) performance is compared with field data collected using an instrumented research vehicle and to Weidemann 99 in VISSIM. Performance metrics were selected to align with state department of transportation work zone management efforts. Results showed acceptable performance from the DLL, as it predicted queue locations and travel speeds that were near field observations. Limitations of the DLL and interface are discussed, and opportunities for improving version 2.0 are described.


Author(s):  
Mohsen Kamyab ◽  
Stephen Remias ◽  
Erfan Najmi ◽  
Sanaz Rabinia ◽  
Jonathan M. Waddell

The aim of deploying intelligent transportation systems (ITS) is often to help engineers and operators identify traffic congestion. The future of ITS-based traffic management is the prediction of traffic conditions using ubiquitous data sources. There are currently well-developed prediction models for recurrent traffic congestion such as during peak hour. However, there is a need to predict traffic congestion resulting from non-recurring events such as highway lane closures. As agencies begin to understand the value of collecting work zone data, rich data sets will emerge consisting of historical work zone information. In the era of big data, rich mobility data sources are becoming available that enable the application of machine learning to predict mobility for work zones. The purpose of this study is to utilize historical lane closure information with supervised machine learning algorithms to forecast spatio-temporal mobility for future lane closures. Various traffic data sources were collected from 1,160 work zones on Michigan interstates between 2014 and 2017. This study uses probe vehicle data to retrieve a mobility profile for these historical observations, and uses these profiles to apply random forest, XGBoost, and artificial neural network (ANN) classification algorithms. The mobility prediction results showed that the ANN model outperformed the other models by reaching up to 85% accuracy. The objective of this research was to show that machine learning algorithms can be used to capture patterns for non-recurrent traffic congestion even when hourly traffic volume is not available.


Author(s):  
Karen K. Dixon ◽  
Joseph E. Hummer ◽  
Ann R. Lorscheider

Work zone capacity values for rural and urban freeways without continuous frontage roads were defined and determined. Data were collected using Nu-Metrics counters and classifiers at 24 work zones in North Carolina. The research included analysis of speed-flow behavior, evaluation of work zone sites based on lane configuration and site location, and determination of the location within the work zone where capacity is lowest. It was shown that the intensity of work activity and the type of study site (rural or urban) strongly affected work zone capacity. The data suggested that the location where capacity is reached is also variable based on the intensity of work. For heavy work in a two-lane to one-lane work zone configuration, the capacity values proposed at the active work area are approximately 1,200 vehicles per hour per lane for rural sites and 1,500 vehicles per hour per lane for urban sites. It is recommended that two distinct volumes be used when queue behavior in a freeway work zone is analyzed. The collapse from uninterrupted flow (designated work zone capacity) and the lower queue-discharge volume both should be considered.


Sign in / Sign up

Export Citation Format

Share Document