Final Report Phase 1 - Temporary Wet-weather Pavement Markings for Mork Zones
This project aims to refine and evaluate a paint and drop-on element-based customized for work-zone applications. The pavement marking system under development offers unique value in providing superior guidance to the driver under dry and wet weather conditions. The shorter durability requirements in work zones enable a low-cost alternative to existing higher-cost, more durable products. We expect this special all-weather work zone pavement marking system to promote work zone safety in especially attention-demanding work zones.
Table of Contents
- Summary of the Work Completed
- Summary of Overall Task Progress
- Appendix A-1: Task 1 - Initial Pre-screening of Candidate Pavement Marking Systems
- Appendix A-2: Task 1 and Task 2: Selection and Installation of Three Candidate Pavement Markings Systems at TTI
- Appendix A-3: Task 2 - Human Factors Field Evaluation at TTI
- Appendix B: Task 3 - Preliminary Work Plan for Phase II
Summary of the Work Completed
This final report summarizes the work completed during Phase I of the project. The details of the work performed and associated findings are given in Appendices A-1, A-2, A-3, and Appendix B of this report.
Summary of Overall Task Progress
|Tasks||Start||End||Duration (Days)||% Complete||Days Complete||Days Remaining||N-07||D||J-08||F||M||A||M||J||J||A||S||O||N||D||J-09||F||M||A||M||J||J||A||S||O|
|Phase I Review by AOTR||7/01/08||7/31/08||30||0%||0||30||x|
Task 1: Initial pre-screening of candidate pavement marking systems
This task was completed. A total of 24 pavement marking samples were installed on a New Orleans, LA test deck in November 2007. A time-series of their retained retroreflective properties collected through January 2008. Three prototype all-weathering markings were identified to carry into Task 2.
Task 2: Install markings at TTI rain range and the human factors evaluation
This task was completed. Work on the human factors study began in February 2008. An experimental plan was developed for a dynamic field study of the visibility properties of the three prototype all-weathering markings chosen based on the Task 1 results. The experimental plan was carried out in collaboration with Texas Transportation Institute and a final report issued in the form of a technical paper submitted to the Transportation Research Board 2009 Annual Meeting.
The results of the study found that all three all-weather marking prototypes had statistically the same detection distances in both continuous rain and wet road conditions, which were statistically longer than the conventional glass bead-on-paint markings commonly used in work zones. Based on these results in combination with the results of Task 1 the all-weathering marking construction proposed to be carried forward into the Phase II is:
3M medium size high refractive index dual-optics drop-on elements at a drop rate of 8g/lineal ft in combination with MODOT Type P (or AASHTO M247 Type I) drop-on 1.5 index glass beads at a drop rate of 12g/lineal ft applied in a double-drop onto a high-build waterborne paint applied at a 20 mil wet film thickness.
Task 3: Coordination and logistical planning for field work-zone evaluation for Phase II
This task was completed. A general experimental plan for the Phase II field evaluations of the all-weather work zone pavement marking system was created to serve as the foundation for individual experimental plans required for the Phase II field studies in each candidate state. An experimental plan has been developed as given in Appendix B.
A Request for Proposal (RFP) was also written and circulated to research organizations having working relationships with the two state DOTs that have already committed to participating in Phase II, Washington State and North Carolina.
A formal proposal to conduct the all-weather paint for work zones field evaluation in North Carolina was received from the Department of Civil, Construction, and Environmental Engineering at North Carolina State University. The Department of Civil and Construction Engineering at Oregon State University has also expressed interest and is in the process of preparing their proposal for conducting the field evaluations in Washington State.
Task 4: Final Selection of Work Zones
This task has not yet started.
Duration: 4 Months, Deliverables: QPR
Task 5: Field demonstrations and evaluations
This task has not yet started.
Duration: 8 Months, Deliverables: 2 QPRs
Task 6: Technology Transfer
This task has not yet started.
Duration: 3 Months, Deliverables: Project Final Report
3M Analysis of Product Manufacturability and Purchase Potential
3M currently manufactures and sells All-Weather Paint products for use as maintenance markings in durable pavement marking applications. The temporary all-weather paint for work zones prototypes being optimized in this study will utilize manufacturing techniques similar to the current product. The equipment to apply and install the test product is already in place in many states, or can be developed very quickly with known procedures. The only difference is the application rates, which are easily adjusted via the control levers on the equipment. We see great purchase potential for this product, especially in the event of successful field demonstrations in Phase II work zone field evaluations. Phase I of the project indicated that the experimental markings provided an unequivocal improvement in visibility distances over conventional pavement markings especially under rainy conditions when driver needs better guidance. Many states already have expressed great interest in a product with a reasonable cost that can also provide nighttime visibility under rainy conditions. However, many of these states also rely on research studies that indicate a measurable benefit before they specify such application. Should the improved visibility positively impact the surrogate measures of safety in the field evaluations in Phase II, we foresee a great potential for general acceptance in the marketplace, and eventually an improvement in driver safety especially in work zones.