Information collected during Los Angeles Traffic Durability testing is examined with emphasis on the understanding of driving and braking patterns. A microcomputer vehicle data acquisition system developed by Ford Research Staff was employed to collect the data. A route description for a single clay is presented in terms of vehicle speed and lining temperature histories. Histograms are used to characterize driving patterns from freeway, city, and hill portions of the route. An estima tu of the distribution of brake work from this single day's data indicate that 40% of the brake work was associated with city driving, 30× with freeway driving, and the remaining 30 % was a result of hill driving.