Effect of the Work Zone Double-Fine Law in Texas

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.

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.


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.


2020 ◽  
Author(s):  
◽  
Siyang Zhang

Safety is the top concern in transportation, especially in work zones, as work zones deviate from regular driving environment and driver behavior is very different. In order to protect workers and create a safer work zone environment, new technologies are proposed by agencies and deployed to work zones, however, some are without scientific study before deployment. Therefore, quantitative studies need to be conducted to show the effectiveness of technologies. Driving simulator is a safe and cost-effective way to test effectiveness of new designs and compare different configurations. Field study is another scientific way of testing, as it provides absolute validity, while simulator study provides relative validity. The synergy of field and simulator studies construct a precise experiment as field study calibrates simulator design and validates simulator results. Two main projects, Evaluation of Automated Flagger Assistance Devices (AFADs), and Evaluation of Green Lights on Truck-Mounted Attenuator (TMA), are discussed in this dissertation to illustrate the investigation of smart work zone technologies using mixed simulator and field studies, along with one simulator project investigating interaction between human driven car and autonomous truck platoon in work zones. Both field and simulator studies indicated that AFADs improved stationary work zone safety by enhancing visibility, isolating workers from immediate traffic, and conveying clear guidance message to traffic. The results of green light on TMAs implied an inverse relationship between visibility/awareness of work zone and arrow board recognition/easy on eyes, but did not show if any of the light configurations is superior. Results anticipated for autonomous truck platoon in work zones are drivers behave more uniformly after being educated about the meaning of signage displayed on the back of truck, and performance measured with signage would be more preferable than those without signage. Applications of statistics are extension of studies, including experimental design, survey design, and data analysis. Data obtained from AFAD and Green Light projects were utilized to illustrate the methodologies of data analysis and model building, which incorporated simulator data, biofeedback and survey response to interpret the relationship among driver perspective and mental status, and driving behavior. From the studies conducted, it could be concluded that mixed simulator and field study is a good fit for smart work zone technologies investigation. Simulators provide a safe environment, flexibility and cost-effectiveness, while field studies calibrate and validate simulator setup and its results. The collaboration of two forms of study generates legitimate and convincing results for investigations. Applying statistical methodologies into transportation simulator and field studies is a good way to make experiment and survey design more rational, and the statistical methods are applicable for further data analysis.


Author(s):  
Ashim Kumar Debnath ◽  
Ross Blackman ◽  
Narelle Haworth ◽  
Yusuf Adinegoro

Remotely operated devices for traffic control—portable traffic lights and automated flagger assistance devices—are used to improve flagger safety in a one-lane-each-way work zone with lane closure. Previous research has measured the effectiveness of these devices as driver compliance rates and driver understanding of the devices, but the effects of these devices on driver behavior have not yet been examined comprehensively. Therefore, the influence of remotely operated stop–slow traffic control devices on driver behavior was examined. Video-recorded traffic movements from a rural work zone in the Queensland state of Australia provided driver speeds, deceleration profiles, stopping behavior, and compliance rates for a set of remotely operated devices new to Australia: static red–amber–green lights, static red–amber lights, static red–amber arrow lights, and mechanical stop–slow signs. Pneumatic tube traffic counters were used to collect driver speeds before and after the devices, and an on-road driver survey was conducted to elicit driver understanding of the devices. Results indicated that drivers had difficulty understanding the new devices, particularly the amber light and amber arrow options (which confused drivers about their meaning—to stop or to go). The new remotely operated devices resulted in higher approach speeds, greater variability in approach speeds, and faster deceleration rates than the flagger method. The good compliance rates observed with the remotely operated devices imply that the devices could improve flagger safety by reducing flagger exposure to traffic; however, the negative effects on driver behavior might indicate an increased risk of rear-end crashes in the advance warning area.


Author(s):  
Gerald L. Ullman

Research conducted to explore the effects of natural diversion on traffic conditions and travel patterns upstream of temporary work zone lane closures on high-volume urban freeways in Texas is described. Specific objectives were to explore how natural diversion affects traffic volumes at the exit and entrance ramps upstream of the lane closures and the interrelationships between the freeway and frontage road operating conditions that develop at a closure and the amount of natural diversion that occurs. The field studies showed that the rate of queue growth upstream of the short-term lane closures diminished significantly after the first hour at each site. Eventually, the queues approached a balanced state in which the upstream end of the queue became almost stationary. This stabilization was due to significant reductions in entrance ramp volumes both upstream of the freeway queue and within the limits of queuing, as well as to changes in exit ramp volumes within the queue. As a result of these ramp volume changes the constrained flow rate within the queue increased as a function of the distance upstream of the actual lane closure. Using the theory of shock waves in a traffic stream it was shown that the changes in ramp volumes and resulting impact on constrained freeway flow rates within the queue were consistent with the queue stabilization process observed at each site.


Author(s):  
Melisa D. Finley

Automated flagger assistance devices (AFADs) are designed to be operated remotely by a flagger positioned outside of the travel lanes and thus to reduce the flagger's exposure to vehicular traffic. There are two types of AFADs. One type uses a remote-controlled stop and slow sign to alternate the right-of-way; the other uses remote-controlled red and yellow lenses to alternate the right-of-way. A gate arm is required only with the latter. Although AFADs may have increased the safety of flaggers, there were concerns that motorists may have misunderstood AFADs and proceeded before it had been safe to do so. As part of a recent Texas Department of Transportation project, Texas A&M Transportation Institute researchers conducted field studies at lane closures on two-lane, two-way roadways in Texas to assess the operational and safety effectiveness of AFADs relative to the use of flaggers. The research findings show that the violation rate for the stop–slow AFAD without a gate arm is the highest and is significantly higher than the violation rate for the red–yellow lens AFAD (which requires a gate arm). Adding a gate arm to the stop–slow AFAD decreased the violation rate such that it was not significantly different from the red–yellow lens AFAD. In addition, alternative supplemental signs increased motorists' understanding that the stop sign would have changed to a slow sign when motorists were allowed to proceed. Overall, the research findings show that some motorists violate AFADs, especially when the queue of vehicles going in the same direction is visible to the stopped motorist.


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.


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.


Author(s):  
Roger P. Bligh ◽  
King K. Mak ◽  
Lewis R. Rhodes

Proper traffic control and delineation are critical to achieving safety in work zones. However, the work zone traffic control devices themselves may pose a safety hazard to vehicle occupants or work crews when impacted by errant vehicles. Thus, there was a need to research the safety performance of work zone traffic control devices to ensure that they perform satisfactorily and meet NCHRP Report 350 guidelines. Several research studies sponsored by the Texas Department of Transportation evaluated the impact performance of various work zone traffic control devices, such as temporary and portable sign supports, plastic drums, sign substrates for use with plastic drums, traffic cones, and vertical panels. Specifically addressed are the studies on barricades. Standard wooden barricade construction was found to be unacceptable due to a demonstrated potential for intrusion of fractured members into the occupant compartment. In response to deficiencies identified in the wooden barricade tests, several alternate barricade designs were developed and successfully tested.


Author(s):  
Ashish Kumar Agarwal ◽  
Daulat Singh Meena ◽  
Vijay Pathak ◽  
Anoop Jain ◽  
Rakesh Kumar Ola

Background: The aim of the present study was to study the effect of percutaneous balloon mitral  valvuloplasty (PBMV) on P wave dispersion and to test the correlation between P-maximum and  P-dispersion to right ventricular function and pulmonary artery pressure before and after PMBV. Also to study the impact of P-maximum and P-wave dispersion on the short term clinical outcome after successful PBMV in patients with mitral stenosis (MS) and sinus rhythm. Methods: 75 patients undergoing PMBV were enrolled in this study. We evaluated P-maximum, P-minimum and P-wave dispersion before and one month and one year after PBMV . We studied the changes in pulmonary arterial pressure (PAP), left atrial (LA) dimension, mitral diastolic gradient, and mitral valve area, in addition to the changes in right ventricular function utilizing tissue Doppler assessment both before and after PMBV, in addition the role of the P-wave dispersion in prediction of late cardiac events. Results: There were significant decrease in mean diastolic gradient, PAP, and LA size and significant improvement in right ventricular tissue Doppler indices after PMBV. Accompany these hemodynamic changes after PMBV. P-maximum and P-wave dispersion were found to be decreased (P < 0.001). Conclusion: Successful PBMV was associated with a decrease in Pmax and PWD. These simple electrocardiographic indices may predict the success of the procedure immediately after PBMV.  The P-maximum and P-wave dispersion changes were correlated with significant impairment of right dysfunction and the degree of pulmonary artery pressure. Keywords: PBMV.PAP,LA


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