scholarly journals Comparing Three Lane Merging Schemes for Short-Term Work Zones: A Simulation Study

2012 ◽  
Vol 2012 ◽  
pp. 1-18 ◽  
Author(s):  
Rami Harb ◽  
Essam Radwan ◽  
Vinayak V. Dixit

Traffic safety and mobility of roadway work zones have been considered to be one of the major concerns in highway traffic safety and operations in Florida. Dynamic lane merging (DLM) systems—ITS-based lane management technology—were introduced by several states in an attempt to enhance both safety and mobility of roadway work zones. Two forms of lane merging, namely, the early merge and the late merge were designed to advise drivers on definite merging locations. Up to date, there are no studies that contrast both merging schemes under matching work zone settings. This study simulates a two-to-one work zone lane closure configuration under three different Maintenance of Traffic (MOT) plans in VISSIM. The first MOT is the conventional plans used in Florida’s work zones, the second MOT is a simplified dynamic early merging system (early SDLMS), and the third MOT is a simplified dynamic late merging systems (late SDLMSs). Field data was collected to calibrate and validate the simulation models. Simulation results indicated that overall, under different levels of drivers’ compliance rate and different percentages of trucks in the traffic composition, the early SLDMS outperformed the conventional MOT and the late SDLMS in terms of travel times and throughputs.

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 G. Beacher ◽  
Michael D. Fontaine ◽  
Nicholas J. Garber

The traffic control strategy of the late merge in work zones was devised to improve flow and safety at work zone lane closures. Although some states have put the strategy into practice, only a handful of short-term field studies have formally evaluated its effectiveness. Additional field studies were necessary to assess the efficacy of the strategy and its proper deployment. This paper documents the results of a field test of the late merge traffic control conducted over several months. The late merge strategy was evaluated by comparing its effectiveness with that of traditional plans for work zone lane closures. The field test was conducted on a primary route in Tappahannock, Virginia, at a two-to-one lane closure. Results showed that throughput increased, but the increase was not statistically significant. Likewise, time in queue decreased, but the decrease was not statistically significant. These results were much less dramatic than those of other studies. Possible reasons for this disparity include different driver populations, road types, vehicle mixes, and site-specific characteristics. Despite limited improvements in throughput and time in queue, more drivers were in the closed lane, a positive response to the late merge signs.


2019 ◽  
Vol 11 (2) ◽  
pp. 382
Author(s):  
Chi Zhang ◽  
Jihan Qin ◽  
Min Zhang ◽  
Hong Zhang ◽  
Yudi Hou

In order to create a practical road-resistance function for work zones under different lane occupation conditions, the expected speed of vehicles was calibrated in the work zone simulation model based on measured data, and simulation models were constructed for the closed half lane and the closed inside lane under different rates of trucks. Based on the statistical theory, the influence of significance of traffic volume and truck ratios for road resistance was analyzed, and a suitable truck ratio was found for the work zone. By using the optimal nonlinear fitting theory, the practical road-resistance function for work zones under different lane occupation conditions was constructed. The results showed that the road resistance is significantly affected by the traffic volume and rate of trucks. Under the same truck ratio, the road resistance linearly increases slowly when the traffic volume is less than the critical traffic volume and rapid increases irregularly when it is greater than the critical traffic volume. Under the same traffic load, the road resistance of the work zone increases with the increase in the rate of trucks, and the difference is not obvious when the traffic volume is less than the critical traffic volume, and increases gradually when it is greater than the critical traffic volume. Through the goodness of fit test and the homogeneity of variance test, the road-resistance function constructed in this paper has high goodness of fit. The practical road-resistance functions constructed in this study could be used to guide the diversion of the rebuilt/expanded highway to ensure traffic safety. Further, the study provides a theoretical basis for the construction of intelligent highway work zones.


Author(s):  
Gerald L. Ullman ◽  
Paul J. Carlson ◽  
Nada D. Trout

Results of research conducted to investigate the short-term effects of the double-fine law in work zones implemented in Texas on January 1, 1998, are presented. Field studies of traffic speeds in several work zones were performed before and after the law was implemented. Traffic citation data for these same work zones were also obtained from the Texas Department of Public Safety. Analyses showed that traffic speeds in the work zones 4 to 6 months after the law was enacted were essentially unchanged from before the law was enacted. Similarly, citation frequency and fines levied were not significantly higher than they were before enactment of the law. The data suggested that a higher proportion of drivers who were issued citations after the law was implemented chose to take defensive driving training and to have the ticket subsequently dismissed. However, researchers could not determine whether this was due to the increased fine or to other external reasons.


2013 ◽  
Vol 409-410 ◽  
pp. 1374-1378 ◽  
Author(s):  
Ke Man Wu ◽  
Lian De Zhong

Via microscopic traffic flow simulation, based on the theory of traffic capacity and queue delay of vehicles on work zones and relying on the Reconstruction and Widening of Fekai Expressway, the paper gives suggested values of minimum space between adjacent work zones in the same direction under different traffic volumes and traffic compositions for references, during the construction of a two-way-8-lane highway with half road way closed. The result can promote work zone traffic safety.


2018 ◽  
Vol 2018 ◽  
pp. 1-16
Author(s):  
Przemysław Sekuła ◽  
Zachary Vander Laan ◽  
Kaveh Farokhi Sadabadi ◽  
Mirosław J. Skibniewski

This paper proposes a clustering approach to predict the probability of a collision occurring in the proximity of planned road maintenance operations (i.e., work zones). The proposed method is applied to over 54,000 short-term work zones in the state of Maryland and demonstrates an ability to predict work zone collision probabilities. One of the key applications of this work is using the predicted probabilities at the operational level to help allocate highway response teams. To this end, a two-stage stochastic program is used to locate response vehicles on the Maryland highway network in order to minimize expected response times.


Safety ◽  
2020 ◽  
Vol 6 (3) ◽  
pp. 38
Author(s):  
Jiří Ambros ◽  
Richard Turek ◽  
Jan Elgner ◽  
Zuzana Křivánková ◽  
Veronika Valentová

The goal of section speed control is to increase speed limit compliance in the monitored road sections, decrease speed variance and improve traffic safety. General experience with section speed control on motorways is positive, with significant improvements in both speed and safety performance. The presented study focused on a unique application of section speed control in motorway work zones in the Czech Republic. Effectiveness was monitored (in terms of average speed, speeding and accident rates) in three sections and four time periods (normal operation, work zone, work zone with section speed control, normal operation), which allowed discerning individual effects of work zone and section speed control. In addition, a novel data source—floating car data—was used. Work zones were found to increase accident rates compared to normal operation and decrease with the introduction of section speed control. The effects on average speed, speed variance and speeding were positive, although smaller compared to the studies conducted in non-work zone conditions.


Author(s):  
Nawaf M. Alshabibi ◽  
Elena Prassas

New York City infrastructure is one of the oldest transportation infrastructures in the United States. Local street construction and short-term work zones are almost continuously planned events that affect the movement of traffic on city streets by requiring the closing of one or more lanes at intersections throughout NYC, and it is important to understand the effect on capacity due to such work. This paper looks at the effect of short-term work zones on the capacity of signalized intersections in New York City. Data was collected at five locations in New York City, both during the work zone and then again after the work zone was removed. Over 25 hours of video data was collected and reduced. It was found that at all locations, the saturation headway was smaller during the work zone compared to after the work zone was removed, that is, the saturation flow rate per lane increased during the work zone. This was an unexpected result. A possible reason for this is the increased traffic pressure that drivers feel when a lane is closed. Thus, although overall approach capacity does decrease because a lane is closed, it did not decrease as much as expected. The field values are then compared with those from two other models: the Highway Capacity Manual model and a model developed by Schroeder et al. It was found that both models underestimate the capacity of the approach.


2019 ◽  
Vol 2019 ◽  
pp. 1-9 ◽  
Author(s):  
Kairan Zhang ◽  
Mohamed Hassan

Egypt’s National Road Project is a large infrastructure project aiming to upgrade the existing network of 2500 kilometers as well as constructing new roads of 4000 kilometers to meet today’s need. Increasing highway work zones eventually direct the challenges for traffic safety and mobility. Realizing the need for mitigating the impact of such a challenging scenario, this paper aims to investigate and identify the factors of work zone rear-end crash severity. In this regard, a random parameter ordered probit model was applied to analyze data on the Egyptian long-term highway work zone projects during the period of 2010 to 2017. The factors of speeding and foggy weather conditions are found to be the key indicators for modeling the random parameters. Besides, during the weekend and at nighttime, there is a higher risk of rear-end crash in work zones, while heavy and passenger vehicles are at greater risk in this regard. It is anticipated that the findings of this study would facilitate transport agencies in developing effective measures to ensure safe mobility across work zones.


2016 ◽  
Vol 28 (3) ◽  
pp. 277-289
Author(s):  
Jin Xin Cao ◽  
Xiao Han Liu

Increasing traffic demand has already reached the capacity of existing traffic facilities in most cities. In order to alleviate the traffic pressure and expand the capacity of the road network, constructing flyovers has become an effective way in most cities in China. During the period of the flyover construction, work zones occupy road space, impact traffic flow characteristics and driver behaviour; therefore, this causes a significant reduction of the capacity. Researching of the traffic flow characteristics during the period of flyover construction can improve traffic organization and traffic safety around work zones. This study analyses the traffic flow characteristics around the flyover work zone based on the site data collected in Hohhot City, China. This study shows that the traditional Logistic model for the equilibrium speed-density relationship is not applied to the traffic flow around the flyover work zone. Based on an in-depth analysis of the traffic flow characteristics and specific driver behaviours, this paper proposes an improved Logistic model to depict the equilibrium speed-density relationship around the flyover work zone. To analyse the mathematical characteristics of the speed-density relationship, this paper proposes a method to insert virtual data points into the initial data, which can make the fit curve be continuous.


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