Traffic safety is a widespread social concern. Tackling the problem requires understanding the people who are driving. This includes information about driver behavior, but also about perceptions these drivers hold regarding their driving. North Dakota crash data points at a specific group ofdrivers as a problem group. Male drivers ages 18 to 34 have a high incident of crash occurrences in our state. This population is selected based on data showing the majority of crashes and crash-related fatalities occurin this population. Specific traffic safety issues seat belt use and impaired driving are major concerns. The answer seems simple, but the problem lies in the question, “how can we change driving behaviors to reduce or stop the resulting tragedies?” Data is needed to answer this crucial question. Engaging North Dakota drivers in traffic safety surveys and focus groups will enable while providing information that can be condensed into a tool to be used for program planning and countermeasure selection decisions. What things will give the DOT the most “bang for the buck” in traffic safety education, policies, and investment for target populations?LCPC (Central Laboratory for Roads and Bridges, a French public research laboratory) has been developing a new concept of concrete pavement of fiveyears. It is based on the following ideas: (1) High-performance concrete shows unique qualities with regard to pavement applications, like high tensile strength, durability, freeze-thaw resistance, abrasion resistance and prevention of steel corrosion; (2) but economy does not promote the useof HPC in conventional pavement, since the gain in flexural strength leads to a decrease in slab thickness, which does not compensate the increase of material unit cost (i.e. the cost per unit surface increases when replacing normal-by high-strength concrete); and (3) HPC qualities are mostly desirable at the top surface of the pavement. Therefore, HPC Carpet consists in a thin, 60-mm HPC wearing course, reinforced by a welded wire mesh, cast upon a conventional concrete (or cement-treated material) structural layer. Thanks to a complex of polymer and geotextile, there is no bond between the two layers, so that reflexive cracking from the base to the course layer is avoided. However, cracking due to traffic loads is permitted in both directions, the dense reinforcement being supposed to maintain thecourse layer integrity. The paper will give an overview of this research, which encompassed design calculations, thermal instability verification,fatigue tests on a 10-mm full scale model and an experimental construction site near Lyon (France). Here, a 120-m long test section has been builtin 2003, and it is currently submitted to heavy truck traffic. To date, the behavior is excellent. In conclusion, the economical potential of this new concept will be highlighted. Rehabilitation of old concrete pavements - where slabs are partly cracked, with moderate rocking - appears as a promising market.
Samenvatting