Revisiting the Influence of Crash Report Forms on Work Zone Crash Data

2004 ◽  
Vol 1897 (1) ◽  
pp. 180-182 ◽  
Author(s):  
Gerald L. Ullman ◽  
Tracy A. Scriba
Keyword(s):  
Safety ◽  
2021 ◽  
Vol 7 (1) ◽  
pp. 12
Author(s):  
Bertha Santos ◽  
Valdemiro Trindade ◽  
Cláudia Polónia ◽  
Luís Picado-Santos

Several studies have shown that European police crash reports provide different detail degrees of work zone crash-related data. In this sense, the present study aims to verify the possibility of identifying significant risk factors involved in the occurrence of road work zone crashes with casualties, based on the official data usually available, through a descriptive, binary logistic, and probit regression statistical analysis. To accomplish the analysis, a total of 2597 police-reports related to 1767 Portuguese work zone crashes that occurred during the 2013–2015 period were considered and binary logistic and probit regression models were estimated by the main type of crash, contributing factor, and driver age group. Fifteen explanatory variables, selected based on the literature review and crash data provided in police crash reports, were considered in the analysis. The results obtained for the estimated coefficients and goodness-of-fit test values were found very similar for both link functions (logit and probit) and it was possible to identify risk factors. The modeling results pointed to excessive speed, disregard for vertical signs, luminosity, intersections, and motorcycle and heavy vehicle involvement as the most significant risk factors. Given the results, it is possible to conclude that binary logistic regression can be used in the statistical analysis of the available police official work zone crash data to identify and get some insight into the risk factors involved in work zone crashes. Data analysis also revealed the need to promote adequate and complete crash report filling by police officers. While police crash reports are not revised and standardized to incorporate more detailed work zone crash information, this approach can be used to support a more efficient road operation decision making and the review of some aspects related to work zone layout design.


2016 ◽  
Author(s):  
◽  
Zhongyuan Zhu

Transportation agencies faced with the challenge of enhancing safety on roadways are looking for alternative solutions to designing roads and signage. When deciding whether the alternative design is superior to the traditional one, decision makers need methods and quantitative data to evaluate these alternatives. This dissertation provides two accessible methods to compare different alternative designs and illustrates them using case studies. The first method involves using speed-based statistical measures that are extracted from video-based traffic surveillance. This method was more accurate in collecting vehicle speeds than the speeds extracted from video-based data collection systems. It was then utilized to evaluate the effectiveness of an alternative merge sign in work zones. This alternative sign consists of an arrow pointing the merge direction and text describing the lane closure, while MUTCD sign is graphical. The case study measured driver behavior characteristics including speeds and open lane occupancies. The results indicate that open lane occupancy was higher for the test sign in comparison to the MUTCD sign upstream of the merge sign. The occupancy values at different distances between the merge sign and the taper were similar for both the test and MUTCD signs, but the test sign encouraged up to 11% more cars to be in the open lane immediately upstream of the merge sign. Passenger cars stayed in the closed lane longer, or closer to the taper, than trucks. The merging behavior of truck drivers did not vary significantly with the type of merge sign deployed in the work zone. The analysis of speed characteristics did not reveal substantial differences between the two sign configurations. The mean speeds with the MUTCD configuration were 1.3 mph and 2 mph lower than the test configuration at the merge sign and taper locations, respectively. The second method utilizes microscopic traffic simulation to evaluate alternative designs. This method is ideal for projects where video monitoring of the entire study of interest is not feasible. Evaluating alternative designs with crash data usually requires a long time span to build the facility and record crash data over at least one year after the facility has been open to traffic. In addition to that, new facility needs to be built or altered if other design features are to be tested. With microscopic simulation, the time cost for the study is greatly shortened and different design aspects can be tested in a risk-free environment. Two case studies are presented to illustrate this simulation method. The first case study involves a work zone while the second case study focuses on evaluating a J-turn intersection design. The spacing of U-turn and the inclusion of acceleration and deceleration lanes were evaluated, in the J-turn study. A simulation analysis was conducted to study the impact of different design variables on the safety of J-turns. A base simulation model was created and calibrated using field data collected in a previous Missouri Department of Transportation (MoDOT) project on J-turns. The calibrated model was then used to study various combinations of major road and minor road volumes and design variables. The simulation analysis helped develop guidance on recommended spacing for various major road and minor road volume scenarios. For all the studied scenarios, the presence of acceleration lane resulted in significantly fewer conflicts. Thus, acceleration lanes are recommended for all J-turn designs, including lower volume sites. Second, while U-turn spacing between 1000 feet and 2000 feet was found to be sufficient for low volume combinations, a spacing of at least 1500 feet and 2000 feet are recommended for medium and high volumes, respectively.


Author(s):  
Shyam Venugopal ◽  
Andrzej Tarko

Construction and maintenance work zones have traditionally been hazardous locations within the highway environment. Studies show that the accident rates during road construction are generally higher than during periods of regular traffic operations. The increase in the number of crashes may be attributed to ( a) general disruption to the flowing traffic due to sudden discontinuities caused by closed lanes, ( b) improper lane merging maneuvers, ( c) the presence of heavy construction equipment within the work area, ( d) inappropriate use of traffic control devices, and ( e) poor traffic management. Research was conducted to develop regression models predicting the expected number of crashes at work zones on rural, two-lane freeway segments. Crashes on approaches to work zones and those inside the work zones were analyzed separately. For developing these models, an extensive database was obtained, including freeway data, crash data, and work zone characteristics. Negative binomial models were developed with average daily traffic, the length of the work zones, and the duration of the work projects as exposure-to-risk variables. The cost of the various work projects was found to be a good substitute for some of the exposure-to-risk variables. The investigated variables included the number of on and off ramps, both on approaches and inside the work zones; the type of work; and the intensity of the road work involved. The models may be used to evaluate beforehand the expected number of crashes on the work zone, given the work zone characteristics.


2010 ◽  
Author(s):  
Jason Wyatt ◽  
Michael Alexander
Keyword(s):  

Author(s):  
John S. Miller ◽  
Duane Karr

Motor vehicle crash countermeasures often are selected after an extensive data analysis of the crash history of a roadway segment. The value of this analysis depends on the accuracy or precision with which the crash itself is located. yet this crash location only is as accurate as the estimate of the police officer. Global Positioning System (GPS) technology may have the potential to increase data accuracy and decrease the time spent to record crash locations. Over 10 months, 32 motor vehicle crash locations were determined by using both conventional methods and hand-held GPS receivers, and the timeliness and precision of the methods were compared. Local crash data analysts were asked how the improved precision affected their consideration of potential crash countermeasures with regard to five crashes selected from the sample. On average, measuring a crash location by using GPS receivers added up to 10 extra minutes, depending on the definition of the crash location, the technology employed, and how that technology was applied. The average difference between conventional methods of measuring the crash location and either GPS or a wheel ranged from 5 m (16 ft) to 39 m (130 ft), depending on how one defined the crash location. Although there are instances in which improved precision will affect the evaluation of crash countermeasures, survey respondents and the literature suggest that problems with conventional crash location methods often arise from human error, not a lack of precision inherent in the technology employed.


Author(s):  
Tianpei Tang ◽  
Senlai Zhu ◽  
Yuntao Guo ◽  
Xizhao Zhou ◽  
Yang Cao

Evaluating the safety risk of rural roadsides is critical for achieving reasonable allocation of a limited budget and avoiding excessive installation of safety facilities. To assess the safety risk of rural roadsides when the crash data are unavailable or missing, this study proposed a Bayesian Network (BN) method that uses the experts’ judgments on the conditional probability of different safety risk factors to evaluate the safety risk of rural roadsides. Eight factors were considered, including seven factors identified in the literature and a new factor named access point density. To validate the effectiveness of the proposed method, a case study was conducted using 19.42 km long road networks in the rural area of Nantong, China. By comparing the results of the proposed method and run-off-road (ROR) crash data from 2015–2016 in the study area, the road segments with higher safety risk levels identified by the proposed method were found to be statistically significantly correlated with higher crash severity based on the crash data. In addition, by comparing the respective results evaluated by eight factors and seven factors (a new factor removed), we also found that access point density significantly contributed to the safety risk of rural roadsides. These results show that the proposed method can be considered as a low-cost solution to evaluating the safety risk of rural roadsides with relatively high accuracy, especially for areas with large rural road networks and incomplete ROR crash data due to budget limitation, human errors, negligence, or inconsistent crash recordings.


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