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Smart Phone Based Forward Collision Warning Messages in Work Zones to Enhance Safety and Reduce Emissions
Abstract
Collisions in work zones have always been a contributing factor in compromising safety on urban roadways. National Highway Traffic Safety Administration (NHTSA) and State Transportation Authorities have implemented many safety countermeasures to reduce forward collision in work zones. However, due to the complexity of traffic in work zones, traditional countermeasures often fail to prevent crashes. As such, smart warning systems could be very helpful in notifying motorists about upcoming conditions within work zones. In this study, a smartphone-based warning system was designed to investigate the effectiveness of advanced warning and notifications on the reduction of forward collisions in a work zone. Four different warning messages were prepared (visual, sound, male voice and female voice) to alert drivers. Driving simulator tests with eighteen participants, driving through a work zone for ninety rounds, were conducted to investigate the impact of smart-phone based warnings on performance measures, including headway distance, headway time, speed, deceleration, and emissions. Statistical results show that, with the help of voice (either female or male) warnings on forward collisions, acceleration rate and speed were significantly lower; and headway time and distance were significantly longer. The sound and voice warnings are beneficial to the reduction of total vehicle emissions. Moreover, participants found the notification system being user friendly and helped to avoid rear-end crashes in work zones.
... Consequently, designing the HMI with in such a way that is fully attuned to the various complexities drivers encounter is crucial. As an illustration, a simulator study by Qiao et al. (2015) investigated the optimal modalities to warn drivers about potential forward collisions in work zone advance warning area using smartphone-generated warnings. Findings reveal that forward collision warnings via the visual modality negatively impacted drivers' performance due to the visual distraction imposed by the HMI during a time-critical situation (8). ...
... As an illustration, a simulator study by Qiao et al. (2015) investigated the optimal modalities to warn drivers about potential forward collisions in work zone advance warning area using smartphone-generated warnings. Findings reveal that forward collision warnings via the visual modality negatively impacted drivers' performance due to the visual distraction imposed by the HMI during a time-critical situation (8). Truck drivers are prone to distracted driving. ...
As the race to automated and connected driving accelerates, merging the physical world with the digital user experience has seized the latest headlines in the technology and automotive industries. Nonetheless, integrating every innovative idea to the vehicle without prior and rigorous assessment of their impacts can be detrimental. The Wyoming Department of Transportation (WYDOT) Connected Vehicle (CV) Pilot launched by the US Department of Transportation (USDOT) in 2015 is being deployed over Wyoming's Interstate 80, a vital freight corridor. A suite of CV applications is being piloted to improve the traffic safety and reliability of the corridor. While deploying the supporting technology stands at the epicenter of the program, designing an effective Human Machine Interface (HMI) and User Experience (UX) matching stakeholders' needs is recognized as being equally pivotal for the Pilot's success. In this regard, the University of Wyoming research team has played an instrumental role in supporting the design of effective and user-centered CV applications and HMI for the Pilot's end users, particularly the CV-equipped truck drivers. This study brings forth the key real-world lessons learned in pursuit of this objective. These lessons led to the development of viable recommendations and actionable insights with immediate impacts on the Pilot. Overall, these lessons address 1) The imperative need for CV warnings to prompt the appropriate driver response, 2) Designing the HMI to support driver safety, and 3) Crafting a UX building driver acceptance and propelling widespread adoption in the long haul.
... In terms of the types of message, Fung et al. (2009) found that the beep sound signal is the most effective one to provide the directly stimulus to drivers while a speech message has no benefit [15]. However, a recent simulator test by Rahman et al. (2015) indicated that, female's voice would induce better driving performance in work zone advance warning area [16]. A typical work-zone has four segments: advance warning area, activity area, transition area and termination area. ...
... In terms of the types of message, Fung et al. (2009) found that the beep sound signal is the most effective one to provide the directly stimulus to drivers while a speech message has no benefit [15]. However, a recent simulator test by Rahman et al. (2015) indicated that, female's voice would induce better driving performance in work zone advance warning area [16]. A typical work-zone has four segments: advance warning area, activity area, transition area and termination area. ...
Work-zone crashes have always drawn public attention. A number of fatalities are recorded every year nationwide within work zone areas. Most existing countermeasures have been dedicated more to the advance warning areas, transition areas, and activity areas of work zone, than the termination areas, where drivers might play less attention to safety threats. In this study, the vehicle-to-vehicle communication based left turn warning system was applied at a work zone termination area, which is immediately followed by a T-intersection. The work-zone is located on the minor road side, while left turn vehicles will be appearing from the major street through the said T-intersection. A smart phone application was designed using Android coding system to provide several types of warning messages to drivers. Corresponding scenarios were designed in a driving simulator, and 20 subjects were recruited to participate in the simulation test followed by a questionnaire survey. The subjects received a warning message when driving to the termination area of a work zone on the coming left turn vehicles. Twenty test drivers’ driving speed, acceleration rates, and break reaction distance to the warning messages were studied in four different scenarios. Results show that the smartphone application has a great impact on driving behaviors, especially the female voice and the beep tone warning, which are recommended for possible field tests. Besides, the developed smartphone applications can be further updated for practical applications of similar needs.
... The study concluded that sound and voice (male and female) warnings produced significant benefits in terms of decreasing drivers' speed and increasing headway time and distance. Conversely, visual warnings worsened drivers' performance due to the additional visual workload imposed by the HMI [17]. Another study by You et al. (2016) evaluated the effectiveness of using smartphone audio collision warnings for drivers attempting to turn left in a work zone termination area immediately followed by a T-intersection. ...
Improving work zone safety remains a prime challenge for the transportation sector in the United States. In particular, the frequency and severity of work zone crashes involving large trucks in rural freeways are alarming. Lack of compliance with the instructions provided at work zones results in increased crash risk. In-vehicle advanced warning systems enabled by Connected Vehicle (CV) technology have the potential to prompt appropriate driver response, make navigation more predictable, and improve overall work zone safety. This study falls under the umbrella of the WYDOT Connected Vehicle Pilot Program and seeks to investigate the impacts of the Pilot's real-time weather and work zone notifications on the behavior of truck drivers in rural freeway work zone settings under poor visibility. Twenty professional truck drivers participated in this simulator study. The driving scenarios were designed to mimic the driving conditions experienced on Wyoming Interstate 80. Findings suggest that exposure to the CV notifications has promising safety benefits manifested in improved driver behavior and response. Furthermore, both the weather and work zone notifications acquired high approval from the participants in terms of usefulness and ease of understanding. Nonetheless, the display of multiple work zone warnings on the Human Machine Interface may had introduced little to moderate distraction for some participants. Overall, this study brings forth valuable lessons that are being funneled to support informed decision making to enhance the Pilot's existing Human Machine Interface design.
... Among the diverse purposes of using smartphones, ranging from surfing the Internet to social media posting, the device has also become a safety tool for everyone, but particularly for women (Lindsay et al., 2013;Rahman et al., 2015). The increasing refugee crisis has made it essential to refugees' safety, as shown by UNHCR report (2016). ...
This paper addresses the life and connectivity of Syrian refugees in Turkey. It is founded on an interdisciplinary research project that combines explorative qualitative methods and a Grounded Theory approach with a survey of 380 Syrian participants living in Zeytinburnu, Istanbul. It examines these refugees’ trajectories from the war situation in Syria to Zeytinburnu, and investigates how they have been using smartphones during the conflict, displacement and resettlement; how the use of smartphones affects their daily lives, social connections and integration; and the type of new uses they have discovered as survival and integration strategies. The author builds conceptual categories to describe how the smartphone has become a dispositif and a tool for survival and integration for the Syrian refugees in Turkey. This study also examines the response of Turkish mobile phone companies to the Syrian refugee crisis and the refugees’ need for connectivity, and how Syrian refugees use these telecom services according to their emerging needs in the Turkish and regional context.
... xample,Li et al. (2013)proposed a wireless communication 76 system called pedestrians-to-vehicle (P2V) to enhance the safety in a conflicting traffic area. Based on 77 the P2V, Li and Qiao (2014) developed another wireless communication system for a signalized 78 intersection under a sun glare effect to improve drivers' visibility of signal change.Rahman et al. (2015)79 developed smartphone application to provide drivers with warning messages for the forward collision 80 area in a work zone.Munni et al. (2015)also designed a smartphone application for the advanced 81 warning messages at a signalized intersection under a foggy weather condition. Furthermore, many 82 studies have proven that the strate ...
STOP signs are often physically blocked by obstacles at the corner, forming a safety threat. To enhance the safety at the un-signalized intersection like a STOP sign intersection, a radio frequency identification (RFID) based drivers smart advisory system (DSAS) was developed, which provides drivers with an earlier warning message when they are approaching an un-signalized intersection. In this research, a pilot field test was conducted with the DSAS alarm on an approach towards a STOP sign intersection in a residential area in Houston, Texas. The designed test route covers all turning movements, including left turn, through movement, and right turn. GPS units recorded test drivers’ driving behaviors. A self-developed MATLAB program and statistically significant difference t-test were applied to analyze the impacts of the DSAS messages on drivers’ driving performance, in terms of approaching speed profile, acceleration/deceleration rates, braking distance, and possible extra vehicle emissions induced by the introduction of the DSAS message. Drivers’ preference on the DSAS was investigated by a designed survey questionnaire among test drivers. Results showed that the DSAS alarm was able to induce drivers to drive significantly slower to approach a STOP sign intersection, perform smaller fluctuation in acceleration/deceleration rates, and be more aware of a coming STOP sign indicated by decelerating earlier. All test drivers preferred to follow the DSAS alarm on roads for a safety concern. Further, the DSAS alarm caused the reduction in emission rates through movement. For a general observation, more road tests with more participants and different test routes were recommended.
... By taking advantage of a driving simulator that provides sufficient information relevant to driver behaviors, many variables have been considered in the evaluation of driving performance. Specifically, the speed, time, and headway distance are often used to evaluate safety performance (Li et al., 2015a; Rahman et al., 2015; Tijerina et al., 2004). Reaction time is then classified into perception response time, brake response time, and time to give an action, in various safety studies (Green, 2000; Lamble et al., 1999; Olson and Farber, 2003; Summala, 2000). ...
Due to sun glare disturbances, drivers encounter fatal threats on roadways, particularly at signalized intersections. Many studies have attempted to develop applicable solutions, such as avoiding sun positions, applying road geometric re-directions, and wearing anti-glare glasses. None of these strategies have fully solved the problem. As one of the “Connected Vehicle” practices proposed by the U.S. Department of Transportation, advanced warning messages (AWMs) are capable of providing wireless information about traffic controls. AWM acts as a supplement to conventional signs and signals, which can be blocked by obstacles or natural disturbances, such as sun glare. The drivers’ smart advisory system (DSAS) can provide drivers with AWM. Using a driving simulator this research explores the effects of DSAS messages on driving behaviors under sun glare disturbance. Statistical analyses were applied to assess (1) the negative impacts of sun glare, (2) the compensation of the DSAS AWM to sun glare effects, and (3) the improvement in driving performance due to DSAS AWM. Four performance indexes were measured, including (1) half kinetic energy speed, (2) mean approach speed, (3) brake response time, and (4) braking distance. The effects of the socio-demographic factors, such as gender, age, educational background, and driving experience were also studied. The analytical results illustrate that the DSAS can compensate for reduced visibility due to sun glare and improve driving performance to a normal visual situation, particularly for left turn and through movement.
... In particular, the warning messages come from drivers' personal device. Besides, some studies have demonstrated that audio warning messages could change drivers' driving behaviors, including driving speed and manoeuvre [4][5][6]. Therefore, this research intends to test the effectiveness of the AWM on the drivers' driving behaviros in work zones and intersection clearance for left-turn. ...
Work zones and intersections are hot spots of conflict areas, leading to crashes. Though many efforts have been made to enhance the safety, there is little indication that the crashes in the two types of conflict areas are declining nationwide. Thousands of crashes are recorded every year in the United States, which are mainly attributed by the insufficiency in the traffic controls and drivers' misjudgement. To supplement the conventional traffic controls, a smartphone based audio warning message (AWM) was proposed and tested in driving simulators regarding safety of workers in work zones as well as vehicles at intersections for left-turn. Results show that the AWM is able to effectively increase drivers' awareness of traffic signs and dynamic traffic situations, in particular, in a hazardous situation. The Proposed Smartphone based Warning Messages Crashes are often observed in a conflict area, such as work zones and intersection. Thousands of crashes are recorded in work zones and intersections every year in the United States [1]. The failure of controlling speed limit and drivers' inattention [2] and drivers' misjudgement [3] are the major causes of crashes in work zones and intersections for left-turn, respectively. With regard to this, a smartphone based audio warning message (AWM) was proposed as a supplement to improve drivers' awareness of dynamic traffic situation and perception of traffic controls in work zones, and instruct drivers to turn left safety at intersections. A smartphone is a portable device and the most prevalent communication tool. Audio messages are able to draw drivers' attention more effective than static traffic control signs do [4]. In particular, the warning messages come from drivers' personal device. Besides, some studies have demonstrated that audio warning messages could change drivers' driving behaviors, including driving speed and manoeuvre [4-6]. Therefore, this research intends to test the effectiveness of the AWM on the drivers' driving behaviros in work zones and intersection clearance for left-turn.
... Within this sector, lightduty vehicles including passenger cars and light-duty trucks were the largest contributors with a percentage of 62% [1]. Meanwhile, many studies have demonstrated that vehicle emissions are sensitive to traffic operations [5] and drivers' driving behaviors [6,7]. Some strategies have been applied to address the vehicle emissions such as charging for CO 2 emissions and promoting public transportation, applying intelligent transportation systems (ITS) to improve drivers' driving behaviors, and so on [8][9][10]. ...
Global climate change attributed by CO2 emissions could seriously impact people’s daily lives. According to the statistics, road transport is one of the largest contributors to greenhouse gases. Simultaneously, the increasing number of vehicles, especially vehicle mileages traveled, will continue to induce more CO2 emissions. It is believed that the driving behavior is one of the most important factors that impact the CO2 emissions. However, some other factors may also contribute to the CO2 emissions, for instance, the geometric elements of a roadway. This paper explores the relationship between the horizontal curve radius and CO2 emissions on freeways from field tests under realworld driving conditions through the development of an Emission Factor Model (EFM). The prediction results were also compared with the measured CO2 emissions based on the default emission rates generated from Motor Vehicle Emission Simulator (MOVES). The modeling results indicate that the EFM has better performance for the estimation of CO2 emissions factors for horizontal curves on freeways under free flow conditions with a predicting error of 5.5%, which is much smaller than the one from a method directly estimated from MOVES (16.8%).
... Texas ranked as the State with the most worker deaths in work zones [7] [13]. Intelligent Transportation System (ITS) based Vehicle-to-Infrastructure (V2I) and Connected Vehicle (V2V) technologies have been proposed and tested in various hazardous situations in simulation environments as well on real roads [14][19] . The results were promising. ...
A smartphone warning system is a feasible option to notify motorists about a safety threat and/or pedestrian crossings ahead. In this paper, a smartphone-based warning system was proposed to enhance workers' safety in work zones. Three different warning message systems, including sound, male voice and female voice, were designed to alert drivers. Twenty-four subjects were recruited for a total of ninety-six rounds driving simulator test in a work zone to investigate the impacts of smartphone-based warning messages on subjects' driving performance, in terms of driving speed, speed variation, acceleration, and brake reaction distance. The outcome showed that, with the assistance of the sound and voice (either female or male) warning messages, drivers could effectively reduce their accelerations and speeds. Meanwhile, such a warning system can induce subjects to shorten their brake reaction distances for worker crossings. All participants found that this warning system is applicable to enhance their defensive driving behaviors while driving through a work zone.
Several studies have researched the effect of dynamic message signs (DMSs) on the driving safety in work zones. However, only a few studies have examined the design of DMS control strategies in work zones. The purpose of this study is to investigate the effects of DMS control strategies on driving decisions and behaviors and to improve the driving safety in work zones by changing the content and placement of DMSs. In this study, five control strategies are proposed by combining five DMSs with different contents (“change lane” versus “go straight”). A total of 32 participants participated in this study. Each participant drove in five scenarios in a high-fidelity driving simulator corresponding to strategies 1-5. The results show that the control strategies have a significant effect on drivers’ decisions and behavior (e.g., the driving speed, acceleration, and lateral placement). All strategies reduce the drivers’ speeds and improve their control stability and compliance. After conducting analytic hierarchy process (AHP) analysis, strategy 2 was removed because the approaching speed exceeded the speed limit. The weight vectors of strategies 1, 3, 4, and 5 under free-flow traffic and traffic jam conditions are Ƴfree-flow traffic=0.25,0.28,0.17,0.23 and Ƴtraffic jam=[0.17,0.28,0.2,0.3] , respectively. These results show that strategy 4 is not suitable for free-flow traffic in work zones, while strategies 5 and 3 are suitable for traffic jams in work zones. Strategy 3 is suitable for both free-flow traffic and traffic jams. The first occurrence of a decision sign that contains lane change content is key to the driver’s decision; in addition, the position of signage with such information should gradually be moved closer to work zones with increasing traffic flow.
Work zone intelligent transportation systems (WZITSs) are promoted as a way to improve safety and reduce congestion at work zone locations where traditional traffic management centers do not exist. These systems usually integrate portable changeable message signs and speed sensors with a central control system that automatically determines appropriate messages that are based on current traffic conditions. Manufacturers of these systems claim that WZITSs can warn drivers of downstream congestion, alert drivers to slower speeds ahead, and suggest alternate routes on the basis of prevailing conditions. Transportation agencies are often asked to make decisions on the installation of a WZITS without the benefit of objective information on its expected performance. Relatively few operational tests of these systems have been performed, and the results are not always well documented or conclusive. Agencies need guidance to help them determine whether a WZITS system would improve safety and operations at a specific site. Applications of WZITSs are reviewed, and a series of guidelines for their deployment, based on lessons learned from past tests, is presented.
This study was undertaken to improve the safety of highway construction zones in New Mexico. The authors examined construction-zone accidents in New Mexico for a 3-year period. In contrast to the traditional technique, which relies solely on the accident record system, they utilized the locations and durations of construction activity on rural state highways. The record system was then used to identify accidents at these sites during the period of construction as well as during the identical period in the previous year. In comparison with the prior year, accident experience increased by 26 percent during construction. Contingency tables were used to compare the driver, roadway, and environmental characteristics of accidents before and during construction.
Work zones tend to cause hazardous conditions for drivers and construction workers, because they create conflicts between construction activities and traffic, thus exacerbating the existing traffic conditions. Every effort should therefore be made to minimize the negative impacts of work zones. A clear understanding of work-zone crash characteristics will help to determine appropriate measures to minimize work-zone hazards. This study investigated the characteristics of work-zone crashes that occurred in Virginia from 1996 through 1999. The information on each crash was obtained from police crash records. Each crash was located in one of five areas of the work zone - (a) advance warning, (b) transition, (c) longitudinal buffer, (d) activity, and (e) termination. The percentage distributions were analyzed relative to crash location, crash severity, collision type, and highway type. The proportionality test was used to determine significant differences at the 5% significance level. The results indicate that the activity area is the predominant location of work-zone crashes regardless of highway type, and rear-end crashes are the predominant crash type. The results also indicate that the proportion of sidewipe-in-same-direction crashes in the transition area is significantly higher than that in the advance warning area.
Studies on work zone crashes typically examine a combination of injury, fatal, and property damage crashes to identify factors that contribute to unsafe conditions within work zones. Few studies focus on fatal crashes within work zones, although a clear understanding of the driver, roadway, and work zone conditions associated with fatal crashes will facilitate the development of strategies aimed at improving safety and reducting fatal as well as nonfatal crashes. The Georgia Department of Transportation recently performed a study to identify the manner of collision, location, and construction activity associated with fatal crashes in work zones. This study is expanded further to examine the difference between fatal crash activity within work zones compared with fatal crashes in non-work-zone locations. Using data from three work zone locations in Georgia, fatal crash activity within work zones also was compared with nonfatal crashes within work zones. Finally, fatal crash activity was examined to determine the influence of the work zone activity on the frequency of fatal crashes. The overall findings of the study indicate that the work zone influences the manner of collision, light conditions, truck involvement, and roadway functional classification under which fatal crashes occur. The study also indicates that fatal crashes in work zones are more likely to involve another vehicle than non-work-zone fatal crashes, and fatal crashes in work zones are less influenced by horizontal and vertical alignment than are non-work-zone crashes.
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