durability, permeability, diffusion, absorption Authors:

, some challenges faced by traffic management agencies, and some best practices and lessons learned for developing and deploying of advanced traffic signal

Fatalities and injuries in truck crashes by time of day

The SAE Recommended Practice 51802, Brake Block Effectiveness Rating [I], has the purpose of establishing a uniform procedure for determination and classification of brake effectiveness for commercial vehicle brakes. The practice provides a means to characterize the friction properties of truck brake lining materials in a representative S-cam brake. However, the test has been found to exhibit an unacceptably large range of variability in the implied friction coefficient for the lining. It has been postulated that some of the: variability arises from factors within the brakes that are used for the test-specifically, dimensional tolerances, and possibly friction in the moving parts. A computer model of an S-.cam brake was developed under this work to help examine various brake parameter sensitivi~ties. The model calculates brake torque for a specified set of geometry, friction properties, arid constant input air chamber force. It assumes that the brake is in a state of equilibrium defined by equalized wear rates on the leading and trailing shoe linings. The parameter!sensitivity findings indicate that a potentially significant source of torque variability is related to possible offsets between the drum turning axis and the spiderlshoe assembly centerline. Other

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Administration. Credit-based congestion pricing (CBCP) is a novel strategy which seeks to overcome the negative equity impacts of congestion pricing (CP) by allocating monthly budgets to eligible travelers to spend on congestion tolls. Previous CBCP studies have surveyed public opinion and examined the traffic and travel-welfare impacts of an Austin, Texas application. This work develops the policy further, examining expert opinions, predicting traffic impacts, estimating air-quality changes, and predicting system costs. 17. Key Words pricing options, congestion tolls, Credit-based congestion pricing (CBCP), congestion pricing (CP) 18. Distribution Statement

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IS. Supplementary Notes

This document is available to the public through the National Technical Information Service, Springfield, VA 22161This document is disseminated under the sponsorship of the Department of Transportation in the interest of information exchange. The United States Government assumes no liability for its contents or use thereof. TECHNICAL REPORT STANDARD TITLE PAC