2013 Session: 400

• Development of Evaluation Criterion for Commercially Available Proximity Warning Systems to Prevent Backing Fatalities in Construction Work Zones
  Abstract: Various sensing technologies, such as radars, video cameras, and tag based systems, have been developed and tested to provide hazard warnings to operators in order to prevent collisions within blind areas of construction equipment. However, due to the various construction equipment characteristics, there is no panacea in terms of technology that will work for all types of construction equipment. Therefore, it is necessary to develop criteria for selecting proximity warning systems for specific equipment types. The main objectives of this study were: (1) to select construction equipment types which most frequently cause backing accidents in construction work zones; (2) to establish a generic proximity warning systems selection criteria for selected equipment types; and (3) to select appropriate proximity warning systems for selected vehicle types. From accident and blind area data analysis, pickup and dump trucks were selected for our test. In addition, the sensor selection criteria for both pickup and dump trucks were developed based on eight evaluation factors and criteria which were collected from related publications and specifications from commercially available systems. The selection criteria were validated by 20 external experts in the field of construction safety and sensing. As a result, three sensor systems for pickup trucks and one sensor system for dump trucks were selected based on the developed evaluation criteria.
  Authors: Choe, Soo Young; Leite, Fernanda; Seedah, Dan; Caldas, Carlos
  Authors: Choe, Soo Young; Leite, Fernanda; Seedah, Dan; Caldas, Carlos
  Year: 2013
  Document Type: Paper
  Subject: Maintenance and Preservation; Operations and Traffic Management; Safety and Human Factors
  Session: 400
  Paper Number: 13-0129
• Paralleling Influence of Unscheduled and Scheduled Roadwork Characteristics on Traffic Incident Durations
  Abstract: The review of incident data covering freeways in Tennessee shows that approximately 2% of incidents each year are the result of unscheduled roadworks. While the public is always informed about the scheduled roadworks, most of unscheduled roadworks are initially unknown to the road users in general. The impact of unscheduled roadworks to traffic operations and safety are currently not well documented in the literature. While the literature review found many studies related to work zones, very few are focused specifically on unscheduled roadwork incidents. The objective of this study was therefore, to evaluate and compare the impact of unscheduled and scheduled roadworks to the length of incident durations. Both descriptive statistics and statistical modeling utilizing Generalized Ordered Logit Model (GOLM) and Multinomial Logit Model (MNL) were used. The GOLM model was used due to its less restrictive ability in estimation compared to parallel line models like ordinary ordered logit since it does not ignore the category ordering unlike MNL. Among the factors found to impact the incident durations significantly include, number of lanes closed, the type of lane closed, vehicle involvement, queue formation, means of incident notification, day of the week and the time of the day. There were slight variations in the magnitude of variable coefficients between scheduled and unscheduled models but with relatively same signs among these two. Comparing GOLM and MNL, signs of most variable coefficients were almost identical between the models but with different interpretations.
  Authors: Chimba, Deo; Kutela, Boniphace; Kwigizile, Valerian; Sando, Thobias
  Authors: Chimba, Deo; Kutela, Boniphace; Kwigizile, Valerian; Sando, Thobias
  Year: 2013
  Document Type: Paper
  Subject: Maintenance and Preservation; Operations and Traffic Management; Safety and Human Factors
  Session: 400
  Paper Number: 13-0637
• Prevention of Backing Fatalities in Construction Work Zones: Comprehensive Survey of Current Practices and Procedures
  Abstract: The purpose of this paper is to conduct a comprehensive survey of current practices and procedures on the prevention of backing fatalities in construction work zones. A review of fatal backing incidents has been done and indicates that backing fatalities are a real and immediate hazard to most construction work zones. Procedures and policies are reviewed and discussed in detail. First, general work zone safety hazards are reviewed, particularly blind areas are identified. Second, engineering controls currently in use are examined and explained to help understand what steps can be taken to prevent future backing fatalities. The internal traffic control plan (ITCP) is described as one of the most promising engineering solutions to this issue. An ITCP designates the movement of people and equipment through the work zone in an effort to maximize safety by minimizing hazardous situations in the work zone. Third, administrative controls (including signalers, drivers, and workers-on-foot training) are also discussed. These in-house communication educational directives could help workers understand and use safe practices to prevent future backing fatalities. Fourth, existing technology controls are reviewed for use in aiding equipment operators in identifying when pedestrian personnel are in dangerous areas around their equipment (i.e., back-up camera, radar). Finally, a summary of the review is given, and future research directions are discussed.
  Authors: Fan, Wei; Radley, Lee; Carroll, John Clayton; Choe, Soo Young; Leite, Fernanda; Seedah, Dan; Caldas, Carlos
  Authors: Fan, Wei; Radley, Lee; Carroll, John Clayton; Choe, Soo Young; Leite, Fernanda; Seedah, Dan; Caldas, Carlos
  Year: 2013
  Document Type: Paper
  Subject: Maintenance and Preservation; Operations and Traffic Management; Safety and Human Factors
  Session: 400
  Paper Number: 13-0323
• Effectiveness of Graphic-Aided Portable Changeable Message Signs in Reducing Vehicle Speeds in Highway Work Zones
  Abstract: Portable changeable message signs (PCMSs) have been employed in highway work zones as a temporary traffic control device for decades in the United States. Results of previous research showed that the traditional text-based PCMS had several limitations, such as having a short range of legibility and being difficult to read by elderly and non-English-speaking drivers. A few simulation studies indicated that using graphic-aided PCMSs could likely overcome these limitations. This paper presents the results of field experiments that were conducted to determine the effectiveness of graphic-aided PCMS in reducing vehicle speeds in the upstream of highway work zones. In field experiment Phase I, a full-matrix PCMS was programmed to display a work zone graphic and a flagger graphic, which were similar to the W21-1 sign and W20-7 sign, respectively, specified by the Manual on Uniform Traffic Control Devices. In field experiment Phase II, the PCMS was programmed to display two alternative work zone graphics along with the original work zone graphic. 1,115 and 1,600 valid vehicle speed data were collected during field experiments Phase I and Phase II, respectively. The results of data analysis suggested that graphic-aided PCMSs reduced mean vehicle speeds between 13% and 17% in the upstream of a work zone. This study provided valuable knowledge to government agencies and the transportation industry on how to regulate and implement graphic-aided PCMS in highway work zones.
  Authors: Huang, Yilei; Bai, Yong
  Authors: Huang, Yilei; Bai, Yong
  Year: 2013
  Document Type: Paper
  Subject: Maintenance and Preservation; Operations and Traffic Management; Safety and Human Factors
  Session: 400
  Paper Number: 13-0971
• Bluetooth Vehicle Reidentification for Analysis of Work Zone Diversion
  Abstract: Bluetooth vehicle re-identification technology has potential to improve understanding of driver route choice behavior associated with work zones. The Wisconsin Department of Transportation and the Smart Work Zone Deployment Initiative commissioned work zone diversion studies at four sites: two urban and two rural. Several Bluetooth detectors were deployed in pairs, triples and quadruples to help identify differences in route choice with and without lane closures. In spite of relatively low (and variable) detection rates, comparisons of the number of vehicles using specific routes during closure and non-closure periods revealed differences in driver behavior in urban vs. rural work zones. These techniques provide field data that can supplement conventional methods for estimating work zone diversion. The accuracy of the method can be expected to increase as the number of vehicles with onboard Bluetooth devices rises and Bluetooth detection technology continues to improve.
  Authors: Effinger, Justin; Horowitz, Alan J.; Liu, Yue; Shaw, John
  Authors: Effinger, Justin; Horowitz, Alan J.; Liu, Yue; Shaw, John
  Year: 2013
  Document Type: Paper
  Subject: Maintenance and Preservation; Operations and Traffic Management; Safety and Human Factors
  Session: 400
  Paper Number: 13-2159
• Individual Driver's Speed Change in Response to Speed Photo Enforcement and Police Patrol Car in Work Zones
  Abstract: Speeds of individual vehicles at two locations in a work zone were matched to determine drivers’ response to the presence of police patrol car (Police), speed radar photo enforcement (SPE), and Base condition with no treatment. . Data collection for matching individual speeds was very laborious but gave much more information, such as direct comparison of a vehicle’s speed at the treatment and downstream location, than averaging data (aggregate data) often used in work zone speed studies. This is the first study using the paired approach.Paired t-tests revealed statistically significant speed increases of 6.1 mph and 5.4 mph between the treatment and downstream locations for Police and SPE, respectively, while the speed change for Base condition was not statistically different than 0 mph. Passenger cars had a higher average speed change than heavy vehicles for Police and SPE but lower for Base. The percentage of speeding vehicles at the Treatment location was 76% for Base, 33% for Police, and 26% for SPE. At the Downstream location, the percentage of speeding vehicles was 77% for the Base while for the Police and SPE it increased to 88% and 76%, respectively. Many more drivers sped up in Police (92%) and SPE (85%) than the 48% who sped up in the Base condition. The percentage of vehicles that were not speeding at the Treatment location but sped up such that they were speeding at the Downstream location was 57% for Police and 54% for SPE compared to only 13% for the Base.
  Authors: Lodes, Michael Robert; Benekohal, Rahim F.
  Authors: Lodes, Michael Robert; Benekohal, Rahim F.
  Year: 2013
  Document Type: Paper
  Subject: Maintenance and Preservation; Operations and Traffic Management; Safety and Human Factors
  Session: 400
  Paper Number: 13-4339
• Evaluation of Supplementary Traffic Control Devices for Surveyor Safety Enhancement
  Abstract: Many DOT employees who conduct geodetic/land surveying work alongside a roadway are constantly exposed to fast-moving traffic. Existing studies on traffic control and safety devices are predominately focused on traditional work zones such as construction and maintenance zones. There are limited studies on using traffic control and safety devices to address the safety issues encountered by surveyors at their unique short-term work sites. Information on traffic control and safety devices that can be used to enhance surveyor safety is greatly needed. Therefore, this study aims to evaluate the effectiveness of two traffic control and safety devices for surveyors and other employees whose work cover a large area within predetermined limits. The selected devices are portable rumble strips and warning lights. These devices were tested extensively at actual surveyor work sites in New Jersey. All tests sites were on four-lane two-way urban roadways. The effectiveness of the selected devices was assessed by a set of surrogate safety measures including reduction in mean speed, 85th percentile speed, changes in speed distributions, speed limit compliance, and braking rate. The results show that portable rumble strips overall outperformed the warning lights while both devices positively affected the surrogate safety measures at surveyor work sites. In addition, the combination of the two devices performed more effectively than using them separately. The potential safety benefits and relative ease of use of these devices make them potential traffic control and safety devices for surveyors as well as other employees who work in similar work sites.
  Authors: Yang, Hong; Ozbay, Kaan; Bartin, Bekir; Chien, I-Jy
  Authors: Yang, Hong; Ozbay, Kaan; Bartin, Bekir; Chien, I-Jy
  Year: 2013
  Document Type: Paper
  Subject: Maintenance and Preservation; Operations and Traffic Management; Safety and Human Factors
  Session: 400
  Paper Number: 13-4921
• Motorists Understanding of Automated Flagger Assistance Devices in Work Zones
  Abstract: Automated flagger assistance devices (AFADs) are designed to be remotely operated by a flagger positioned outside of the travel lane, thereby reducing their exposure to vehicular traffic. There are two types of AFADs. One type uses a remotely controlled stop/slow sign to alternately control the right-of-way. The other type uses remotely controlled red and yellow lenses and a gate arm to alternately control the right-of-way. While AFADs may increase the safety of flaggers, there were concerns that motorists may misunderstand AFADs; thus, increasing the potential for motorists to enter the lane closure under the stop condition. As part of a recent Texas Department of Transportation project, Texas Transportation Institute researchers conducted surveys to assess motorist understanding of both types of AFADs.For the stop/slow AFAD, a newly designed WAIT ON STOP/GO ON SLOW symbol sign resulted in the highest percentage of participants who understood to stop and remain stopped until the AFAD indicated that it was safe to proceed. However for all of the treatments evaluated, a portion of the participants indicated they would have stopped and then proceeded instead of waiting until the AFAD displayed the slow sign. Thus, researchers recommend that a gate arm be required with stop/slow AFADs. For the red/yellow lens AFAD, participants understood the stop phase. However, there was evidence of a lack of understanding of the difference between the proceed and transition phases. Even so, the use of the gate arm appeared to inform motorists when to proceed and when to stop.
  Authors: Trout, Nada; Finley, Melisa Dayle; Ullman, Brooke R.
  Authors: Trout, Nada; Finley, Melisa Dayle; Ullman, Brooke R.
  Year: 2013
  Document Type: Paper
  Subject: Maintenance and Preservation; Operations and Traffic Management; Safety and Human Factors
  Session: 400
  Paper Number: 13-4225
  Practice-Ready: Yes
• Development of Evaluation Criterion for Commercially Available Proximity Warning Systems to Prevent Backing Fatalities in Construction Work Zones
  Authors: Seedah, Dan
  Authors: Seedah, Dan
  Year: 2013
  Document Type: Presentation; Poster
  Subject: Maintenance and Preservation; Operations and Traffic Management; Safety and Human Factors
  Session: 400
  Paper Number: 13-0129
• Effectiveness of Graphic-Aided Portable Changeable Message Signs in Reducing Vehicle Speeds in Highway Work Zones
  Authors: Huang, Yilei
  Authors: Huang, Yilei
  Year: 2013
  Document Type: Presentation; Poster
  Subject: Maintenance and Preservation; Operations and Traffic Management; Safety and Human Factors
  Session: 400
  Paper Number: 13-0971
• Bluetooth Vehicle Reidentification for Analysis of Work Zone Diversion
  Authors: Horowitz, Alan
  Authors: Horowitz, Alan
  Year: 2013
  Document Type: Presentation; Poster
  Subject: Maintenance and Preservation; Operations and Traffic Management; Safety and Human Factors
  Session: 400
  Paper Number: 13-2159
• Motorists Understanding of Automated Flagger Assistance Devices in Work Zones
  Authors: Trout, Nada
  Authors: Trout, Nada
  Year: 2013
  Document Type: Presentation; Poster
  Subject: Maintenance and Preservation; Operations and Traffic Management; Safety and Human Factors
  Session: 400
  Paper Number: 13-4225
• Prevention of Backing Fatalities in Construction Work Zones: Comprehensive Survey of Current Practices and Procedures
  Authors: Fan, Wei
  Authors: Fan, Wei
  Year: 2013
  Document Type: Presentation; Poster
  Subject: Maintenance and Preservation; Operations and Traffic Management; Safety and Human Factors
  Session: 400
  Paper Number: 13-0323
• Evaluation of Supplementary Traffic Control Devices for Surveyor Safety Enhancement
  Authors: Yang, Hong
  Keywords: Secondary Crash; Traffic Incident; Sensor Data; Incident Management; Highway Operation; Freeway
  Authors: Yang, Hong
  Year: 2013
  Document Type: Presentation; Poster
  Subject: Maintenance and Preservation; Operations and Traffic Management; Safety and Human Factors
  Session: 400
  Paper Number: 13-4921