Work Zone Simulator Analysis: Driver Performance and Acceptance of Alternate Merge Sign Configurations

Improving work zone road safety is an issue of great interest due to the high number of crashes observed in work zones. Departments of Transportation (DOTs) use a variety of methods to inform drivers of upcoming work zones. One method used by DOTs is work zone signage configuration. It is necessary to evaluate the efficiency of different configurations, by law, before implementation of new signage designs that deviate from national standards. This research presents a driving simulator based study, funded by the Missouri Department of Transportation (MoDOT) that evaluates a driver’s response to work zone sign configurations. This study has compared the Conventional Lane Merge (CLM) configurations against MoDOT’s alternate configurations. Study participants within target populations, chosen to represent a range of Missouri drivers, have attempted four work zone configurations, as part of a driving simulator experience. The test scenarios simulated both right and left work zone lane closures for both the CLM and MoDOT alternatives. Travel time was measured against demographic characteristics of test driver populations. Statistical data analysis was used to investigate the effectiveness of different configurations employed in the study. The results of this study were compared to results from a previous MoDOT to compare result of  field and simulation study about MoDOT’s alternate configurations. 

VIEW REPORT 

Report number: cmr 16-014
Published: June 2016
Project number: TR201512
Author(s): S.K. Long, R. Qin, D. Konur, M. Leu, S. Moradpour, S. Wu
Performing organization: Missouri University of Science & Technology, Department of Engineering Management and Systems Engineering

Self-Consolidating Concrete (SCC) and High-Volume Fly Ash Concrete (HVFAC) for Infrastructure Elements: Implementation

The objective of this research was to provide an implementation test bed and showcase for the use of sustainable and extended service life concrete. In this implementation study for Missouri Bridge A7957, a level of 50% fly ash to cement proportions was utilized as well as normal strength self-consolidating concrete (NS-SCC) and high-strength self-consolidating concrete (HS-SCC) in its primary carrying elements to showcase the use of these innovative materials.  This study focused on monitoring the serviceability and structural performance, both short-term and long-term, of the bridge in an attempt to investigate the in-situ behavior of the NS-SCC, HS-SCC and also the HVFAC mixtures.

Consequently, to compare and demonstrate the potential benefits and savings of using NS-SCC, HS-SCC and HVFAC in the first Missouri DOT large-scale bridge structure, this study undertook ten tasks which include Task 1: Pre-Construction Planning and Construction Coordination; Task 2: Development of Bridge Instrumentation Plan & Load Testing Plan (Bridge A7957); Task 3: Mix Design and Quality Control Procedures/Quality Assurance – Trial Mixes; Task 4: Shear Testing and Evaluation of HS-SCC Precast NU Girders; Task 5: Precast-Prestressed Plant Specimen Fabrication and Instrumentation; Task 6: Field Cast-In-Place Elements and Instrumentation; Task 7: Hardened Properties of Plant and Field Produced Concrete; Task 8: Bridge Load Testing and Monitoring/Evaluation of Experimental Load Testing Results; Task 9: Reporting/Technology Transfer; Task 10: Value to MoDOT and Stakeholders to Implementing SCC/HVFAC.

The final report consists of a summary report and four technical reports. The findings, conclusions and recommendations of the study can be referenced within these reporting components.

VIEW ALL REPORTS

Report number: cmr 16-011 (summary report), cmr 16-011A through D
Published: June 2016
Project number: TR201236
Author(s): Dr. John J. Myers (Project PI), Eli S. Hernandez, Hayder Alghazali, Alexander Griffin, and Kaylea Smith
Performing organizations: Missouri University of Science and Technology

Highway Safety Manual Applied in Missouri – Freeway/Software

AASHTO’s Highway Safety Manual (HSM) facilitates the quantitative safety analysis of highway facilities. In a 2014 supplement, freeway facilities were added to the original HSM manual which allows the modeling of highway interchanges. This report documents the calibration of the most vital freeway interchange facility types in Missouri. These facility types include nine freeway interchange terminals, including diamond, partial cloverleaf, and full cloverleaf interchanges. The non-terminal facilities included entrance and exit speed-change lanes, and entrance and exit ramps. The calibrated facilities applied to both rural and urban locations. For each facility type, sample sites were randomly selected from an exhaustive master list. Four types of data were collected for each site: geometric, AADT, traffic control, and crash. Crash data was especially noteworthy because of the crash landing problem, i.e. crashes were not located on the proper interchange facility. A significant companion crash correction project was undertaken involving the review of 12,409 crash reports, and the detailed review of 9,169 crash reports. Using the corrected data, 44 calibration values were derived for freeway terminal and non-terminal facilities. These values are the first reported freeway interchange calibration values since the release of the 2014 HSM supplement.

VIEW REPORT AND SUMMARY

Report number: cmr 16-009
Published: June 2016
Project number: TR201405
Author(s): Dr. C. Sun, Dr. P. Edara, B. Claros, A. Khezerzadeh, H. Brown and C. Nemmers  

Performing organizations: University of Missouri-Columbia Department of Civil & Environmental Engineering

Crash Location Correction for Freeway Interchange Modeling

AASHTO released a supplement to the Highway Safety Manual (HSM) in 2014 that includes models for freeway interchanges composed of segments, speed-change lanes and terminals. A necessary component to the use of HSM is having the appropriate safety-related data. However, a high percentage, approximately 75 percent, of interchange crashes on the MoDOT TMS systems are landed on an incorrect location within an interchange. For example, crashes are frequently placed in the midpoint of the ramp terminal instead of properly assigned to one of the two ramp terminals. Another example is crashes that are assigned to the freeway mainline when the crashes are related to ramps. In order to properly calibrate and use HSM freeway interchange models, the location of crashes needs to be corrected. The crash landing correction involves the visual inspection of crash images compiled by the Missouri State Highway Patrol. A detailed procedure was established along with a reviewer test so that crash correction can be conducted uniformly among multiple reviewers. A total of 10,897 crashes were reviewed, and 9,168 underwent detailed review and correction. Of the total, 1482 were partial cloverleaf crashes, 5086 were diamond interchange crashes, 780 were ramp crashes, and 1820 were speed-change lane crashes. The crash location correction process helped to eliminate the error rate of 69% associated with interchange crash locations. Any analyst can correct crash locations by following the procedure detailed in this report.

VIEW REPORT AND SUMMARY

Report number: cmr 16-010
Published: June 2016
Project number: TR201504
Author(s): Dr. C. Sun, Dr. P. Edara, B. Claros, A. Khezerzadeh, H. Brown and C. Nemmers  

Performing organizations: University of Missouri-Columbia Department of Civil & Environmental Engineering

System-wide Safety Treatments and Design Guidance for J-Turns

Given their safety effectiveness and low cost, the J-turn has become a preferred alternative to replace high crash two-way stop-controlled intersections on high speed highways. Unfortunately, national guidance on the design of J-turns is very limited.This project addresses this gap by developing guidance for spacing and acceleration lanes. A thorough examination of crashes that occurred at twelve existing J-turn sites in Missouri was conducted. The crash review revealed the proportions of five crash types occurring at J-turn sites: 1) major road sideswipe (31.6%), 2) major road rear-end (28.1%), 3) minor road rear-end (15.8%), 4) loss of control (14%), and 5) merging from U-turn (10.5%). The crash rates decreased with the increase in the spacing to the U-turn, for both sideswipe and rear-end crashes; J-turns with a spacing of 1500 feet or greater experienced the lowest crash rates. A calibrated simulation model was used to study various volume scenarios and design variables. For all scenarios, the presence of acceleration lane resulted in significantly fewer conflicts. Thus, acceleration lanes were recommended for all J-turn designs, including lower volume sites. Second, while spacing between 1000 feet and 2000 feet was found to be sufficient for low volume combinations, spacing of 2000 feet was recommended for medium to high volume conditions.

VIEW REPORT

Report number: cmr 16-013
Published: June 2016
Project number: TR201510
Author(s): Dr. Praveen Edara (Principal PI), Dr. Carlos Sun (co-PI), Henry Brown (co-PI), Boris Claros, Zhongyuan Zhu  
Performing organizations: University of Missouri-Columbia Department of Civil & Environmental Engineering