scholarly journals Control Strategy Optimization for Two-Lane Highway Lane-Closure Work Zones

2019 ◽  
Vol 11 (17) ◽  
pp. 4567 ◽  
Author(s):  
Hua ◽  
Wang ◽  
Yu ◽  
Zhu ◽  
Wang
Keyword(s):  
Control Strategy ◽  
Traffic Control ◽  
Queue Length ◽  
Control Strategies ◽  
Good Alternative ◽  
Management Control ◽  
Work Zone ◽  
Delay Model ◽  
Work Zones ◽  
Two Phase

Traffic control is very important for two-lane highway lane-closure work zone traffic management. Control of the open lane’s right of way is very similar to that of a two-phase signalized intersection. Thus, four control strategies including flagger control, pre-timed control proposed by Schonfeld, pre-timed control proposed by Webster, and actuated control are employed for possible use at work zones. Two primary methodologies, the mathematical delay model adopted from signalized intersections, and the simulation model calibrated with field data, are proposed. The simulation and mathematical results show that control strategies for two one-way road intersections could be used for two-lane highway lane-closure work zones. Flagger control after gap-out distance optimization prevails over all the other control strategies in terms of stopped delay, queue length, and throughput, under low or high volumes. Actuated control could be a good alternative for work zone areas due to its small queue length and large vehicle throughput under moderate volume conditions. Our findings may help to optimize the work-zone control strategy and improve operational efficiency at two-lane highway lane-closure work zones.

Guidelines for Using Late Merge Traffic Control in Work Zones

2005 ◽  
Vol 1911 (1) ◽  
pp. 42-50 ◽  
Author(s):  
Andrew G. Beacher ◽  
Michael D. Fontaine ◽  
Nicholas J. Garber
Keyword(s):  
Control Strategy ◽  
Traffic Control ◽  
Work Zone ◽  
Storage Space ◽  
Heavy Vehicles ◽  
Work Zones ◽  
Microscopic Traffic Simulation ◽  
Traffic Stream ◽  
Flow At Work ◽  
Full Factorial

The late merge traffic control strategy has been proposed as a way to improve flow at work zone lane closures by maximizing queue storage space and creating more orderly merging. The late merge instructs drivers to use all lanes to the work zone taper and then take turns proceeding through the work zone. There is little information available on when the late merge should be used, however, and a limited understanding of the factors that influence its performance. This paper discusses the results of a simulation study of the late merge concept using microscopic traffic simulation. The late merge concept was evaluated by comparing it with traditional traffic control, through a full factorial analysis. Results of the computer simulations showed that the late merge produced a statistically significant increase in throughput volume versus the traditional merge for the three-to-one lane closure configuration across all combinations of analysis factors. Although the two-to-one and three-to-two configurations did not show significant improvement in throughput overall, it was found that as the percentage of heavy vehicles increased, the late merge did foster higher throughput volumes than traditional traffic control. The results of the simulations indicate that the late merge may not provide as much of a benefit as previous studies had indicated and that the area of application for the late merge may be limited to situations where heavy vehicles constitute more than 20% of the traffic stream.

Study and Simulation on the Energy Efficiency Management Control Strategy of Ship Based on Clean Propulsion System

2015 ◽  
Author(s):  
Kai Wang ◽  
Xinping Yan ◽  
Yupeng Yuan
Keyword(s):  
Energy Efficiency ◽  
Energy Consumption ◽  
Control Strategy ◽  
Control Strategies ◽  
Management Control ◽  
Propulsion System ◽  
Power Requirement ◽  
Doubly Fed ◽  
System Configurations ◽  
And Control

Nowadays, with the higher voice of ship energy saving and emission reduction, the research on energy efficiency management is particularly necessary. Energy efficiency management and control of ships is an effective way to improve the ship energy efficiency. In this paper, according to the new clean propulsion system configurations of 5000 tons of bulk carrier, the energy efficiency management control strategy of the clean propulsion system is designed based on the model of advanced brushless doubly-fed shaft generator, propulsion system using LNG/diesel dual fuel engine and energy consumption of the main engine for reducing energy consumption. The simulation model of the entire propulsion system and the designed control strategy were designed. The influence of the engine speed on the ship energy efficiency was analyzed, and the feasibility of the energy efficiency management control strategies was verified by simulation using Matlab/Simulink. The results show that the designed strategies can ensure the power requirement of the whole ship under different conditions and improve the ship energy efficiency and reduce CO2 emissions.

Field Evaluation of Late Merge Traffic Control in Work Zones

2005 ◽  
Vol 1911 (1) ◽  
pp. 33-41 ◽  
Author(s):  
Andrew G. Beacher ◽  
Michael D. Fontaine ◽  
Nicholas J. Garber
Keyword(s):  
Field Test ◽  
Traffic Control ◽  
Positive Response ◽  
Field Evaluation ◽  
Field Studies ◽  
Work Zone ◽  
Work Zones ◽  
Short Term ◽  
Term Field ◽  
Lane Closures

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.

Crash Testing and Evaluation of Work Zone Traffic Control Devices

1998 ◽  
Vol 1650 (1) ◽  
pp. 45-54 ◽  
Author(s):  
King K. Mak ◽  
Roger P. Bligh ◽  
Lewis R. Rhodes
Keyword(s):  
Traffic Control ◽  
Evaluation Criteria ◽  
Work Zone ◽  
Work Zones ◽  
Impact Performance ◽  
Crash Testing ◽  
Control Devices ◽  
Traffic Control Devices ◽  
Under Construction ◽  
The Impact

Safety of work zones is a major area of concern since it is not always possible to maintain a level of safety comparable to that of a normal highway not under construction. Proper traffic control is critical to the safety of work zones. However, traffic control devices themselves may pose a safety hazard when impacted by errant vehicles. The impact performance of many work zone traffic control devices is mostly unknown, and little, if any, crash testing has been conducted in accordance with guidelines set forth in NCHRP Report 350. The Texas Department of Transportation (TxDOT) has, in recent years, sponsored a number of studies at the Texas Transportation Institute to assess the impact performance of various work zone traffic control devices, including plastic drums and sign substrates, temporary and portable sign supports, plastic cones, vertical panels, and barricades. The results, findings, conclusions, and recommendations are presented for temporary and portable sign supports, plastic drums, sign substrates for use with plastic drums, traffic cones, and vertical panels, whereas those for barricades are covered elsewhere. Most of the work zone traffic control devices satisfactorily met the evaluation criteria set forth in NCHRP Report 350 and are recommended for field implementation. However, some of the devices failed to perform satisfactorily and are not recommended for field applications. The results from these studies are being incorporated into the TxDOT barricade and construction standard sheets for use in work zones.

scholarly journals Influence of Remotely Operated Stop–Slow Controls on Driver Behavior in Work Zones

2017 ◽  
Vol 2615 (1) ◽  
pp. 19-25 ◽  
Author(s):  
Ashim Kumar Debnath ◽  
Ross Blackman ◽  
Narelle Haworth ◽  
Yusuf Adinegoro
Keyword(s):  
Traffic Control ◽  
Driver Behavior ◽  
Work Zone ◽  
Work Zones ◽  
Negative Effects ◽  
Traffic Lights ◽  
Increased Risk ◽  
Before And After ◽  
Driver Understanding ◽  
Rural Work

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.

scholarly journals Integrated Traffic Control for Freeways using Variable Speed Limits and Lane Change Control Actions

2019 ◽  
Vol 2673 (9) ◽  
pp. 602-613 ◽  
Author(s):  
Vasileios Markantonakis ◽  
Dimitrios Ilias Skoufoulas ◽  
Ioannis Papamichail ◽  
Markos Papageorgiou
Keyword(s):  
Control Strategy ◽  
Traffic Control ◽  
Traffic Congestion ◽  
Communication Systems ◽  
Feedforward Control ◽  
Control Strategies ◽  
Connected Vehicles ◽  
Variable Speed ◽  
Speed Limits ◽  
Variable Speed Limits

The wide deployment of vehicle automation and communication systems (VACS) in the next decade is expected to influence traffic performance on freeways. Apart from safety and comfort, one of the goals is the alleviation of traffic congestion which is a major and challenging problem for modern societies. The paper investigates the combined use of two feedback control strategies utilizing VACS at different penetration rates, aiming to maximize throughput at bottleneck locations. The first control strategy employs mainstream traffic flow control using appropriate variable speed limits as an actuator. The second control strategy delivers appropriate lane-changing actions to selected connected vehicles using a feedback-feedforward control law. Investigations of the proposed integrated scheme have been conducted using a microscopic simulation model for a hypothetical freeway featuring a lane-drop bottleneck. The results demonstrate significant improvements even for low penetration rates of connected vehicles.

Influence of Exposure Duration on the Effectiveness of Changeable-Message Signs in Controlling Vehicle Speeds at Work Zones

1998 ◽  
Vol 1650 (1) ◽  
pp. 62-70 ◽  
Author(s):  
Nicholas J. Garber ◽  
Srivatsan Srinivasan
Keyword(s):  
Threshold Value ◽  
Video Camera ◽  
Work Zone ◽  
Second Phase ◽  
Volume Data ◽  
Work Zones ◽  
Two Phase ◽  
Changeable Message Signs ◽  
Study Sites ◽  
Message Signs

In work zones, drivers do not slow down in response to conventional signs. Changeable-message signs (CMSs) equipped with a radar unit can be used to display specific warning messages to speeding drivers. The radar unit detects the speed of each vehicle entering the work zone and can be programmed to activate the CMS if the speed of the vehicle exceeds a preset threshold value. A two-phase longitudinal study was conducted. The first phase, conducted by Garber and Patel, examined the short-term effectiveness of the CMS with radar in reducing vehicle speeds in work zones. The second phase, some of the results of which are presented, evaluated the influence of the duration of exposure of the CMS with radar on its effectiveness in reducing speeds in work zones. Speed and volume data for the population were collected at the study sites by automatic traffic counters placed at the beginning, middle, and end of each work zone. In addition, the speeds of individual drivers who triggered the CMS by exceeding the threshold speed were also recorded (using a video camera) at two other locations within the work zone for several weeks and analyzed. The results of the study indicated that the duration of exposure of the CMS does not have a significant impact on speed characteristics and driver behavior. Therefore, the CMS continues to be effective in controlling speeds in work zones for projects of long duration. The results also indicated that the CMS with radar reduces the probability of speeding at work zones and that this effect is maintained for at least up to 7 weeks.

Work Zone Safety Performance: Comparison of Alternative Traffic Control Strategies

2017 ◽  
Vol 2617 (1) ◽  
pp. 87-93 ◽  
Author(s):  
Emira Rista ◽  
Timothy Barrette ◽  
Raha Hamzeie ◽  
Peter Savolainen ◽  
Timothy J. Gates
Keyword(s):  
Traffic Safety ◽  
Traffic Control ◽  
Control Strategies ◽  
Safety Performance ◽  
Work Zone ◽  
Segment Length ◽  
Crash Rates ◽  
Study Results ◽  
Significant Difference ◽  
Lane Closures

Work zone temporary traffic control strategies generally affect both traffic safety and operations. However, there is a substantial gap in the knowledge base with respect to the safety impacts of various work zone characteristics. The Highway Safety Manual provides crash modification functions that account for the effects of project length and duration on crash frequency as compared with normal road operations. However, these methods do not allow for explicit comparisons of expected safety performance among different work or closure types. This research examined the safety impacts of various temporary traffic control strategies on freeways, including shoulder closures, lane closures, and lane shifts. Data were collected for the periods during which these treatments were in effect and during similar nonconstruction periods from the preceding year. Safety performance functions were estimated that account for segment length, duration, traffic volume, and closure type. Random parameter count data models were estimated to accommodate segment-specific temporal correlation and unobserved heterogeneity. Crash rates were shown to vary roughly in proportion to traffic volumes. In contrast, segment length and project duration showed inelastic effects; this finding implies that crash rates increase more rapidly in work zones that are shorter in length or duration. Single-lane closures, multilane closures, and lane shifts were associated with an increase in crashes, whereas shoulder closures did not show a significant difference compared with similar, non-work-zone conditions. Ultimately, the study results provide important information that can be used to assess the crash risk for various temporary traffic control strategies.

scholarly journals Crash Testing and Analysis of Work-Zone Sign Supports

2002 ◽  
Vol 1797 (1) ◽  
pp. 96-104 ◽  
Author(s):  
Karla A. Polivka ◽  
Ronald K. Faller ◽  
John R. Rohde ◽  
Dean L. Sicking
Keyword(s):  
Traffic Control ◽  
Work Zone ◽  
Work Zones ◽  
Design Elements ◽  
Impact Performance ◽  
Crash Testing ◽  
Control Devices ◽  
Traffic Control Devices ◽  
The Impact ◽  
Fundamental Design

A variety of traffic-controlling devices are used in work zones; some of these are not normally found on the roadside or in the traveled way outside of the work zones. These devices are used to enhance the safety of the work zones by controlling the traffic through these areas. Because of the placement of the traffic control devices, the devices themselves may be potentially hazardous to both workers and errant vehicles. The impact performance of many work-zone traffic control devices is mainly unknown, and to date limited crash testing has been conducted under the criteria of NCHRP Report 350: Recommended Procedures for the Safety Performance Evaluation of Highway Features. The results of full-scale crash testing of flexible panel work-zone sign stands were evaluated and analyzed to quantify the features that successful devices shared, as well as common features of those devices that failed salient safety criteria. Parameters considered included sign base and upright properties, sign height, cross-member properties, and ancillary details. Results pointed to three problematic, fundamental design issues: ( a) combinations of base and upright stiffness and strength that generally lead to significant windshield damage, ( b) cross members that lead to windshield damage in the end-on (90°) impact orientation, and ( c) appurtenances that have an impact on performance. Although there are a significant number of variables that control the performance of a given device, these generalizations offer a basis for the evaluation of the fundamental design elements.

Study on Control Design of Interchange Entrance Congestion Zone

2013 ◽  
Vol 361-363 ◽  
pp. 2270-2275
Author(s):  
Xian Guang Wang ◽  
Xiao Nian Sun
Keyword(s):  
Traffic Safety ◽  
Control Strategy ◽  
Traffic Control ◽  
High Speed ◽  
Road Network ◽  
Control Strategies ◽  
Operational Reliability ◽  
Traffic Demand ◽  
Traffic Characteristics ◽  
Overall Reliability

Interchange entrance area is the key point which affects the overall operational reliability of an Interchange. In order to alleviate the crowded ramp merging area, improve the overall reliability of the interchange and improve traffic safety, when traffic demand increases to a certain extent, traffic control strategies should be used. According of the characteristics of the interchange ramp entrance area, the control strategy of interchange and the mainline which affect the reliability of high-speed road network most has been researched. Analyzing the geometric and traffic characteristics of the ramp merging area, different control strategies on the ramp and the mainline are proposed, that is ramp access control strategy and the main line lane running constraint strategy.

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